As Human

Katerina Petrova (Cyrillic Катерина Петрова) was born into a wealthy Bulgarian family on June 5, 1473. Like her descendent before her, Tatia, Katerina was 16 when she gave birth to a daughter Nadia and she ended up being forced into adoption, Katerina was disowned by her family and sent her exile.

It realized Nadia was her daughter who searched her mother for many years.

Season 1

When Katherine learned of the escape of the Vampire's Tomb vampires, she gave her descendant and friend, Isobel Flemming, a Daylight Amulet medallion, enabling the young vampire to walk in the sun. Katherine needed the tomb vampires dead because she didn't want Klaus to find out she was still alive, so she had Isobel retrieve Johnathan Gilbert's Gilbert Device invention and give it to John Gilbert to use against the vampires in Mystic Falls. This resulted in the deaths of the remaining tomb vampires.

In Founder's Day after the chaos has settled, Katherine, having stolen some of Elena Gilbert's clothes, goes to the Gilbert house, where she poses as Elena in the presence of Damon. The two kiss, only to be interrupted by Elena's aunt, Jenna Sommers. Unaware of the presence of vampires or the existence of Katherine, Jenna invites her into the house. Katherine startles John Gilbert in the kitchen, still pretending to be Elena. She notices the Gilbert Ring|magic Gilbert ring he is wearing and, using a butcher's knife, viciously chops his fingers off, then stabs him. Elena arrives and comes to John's aid while Katherine hovers behind her.

Season 2

Seeing John Gilbert seriously injured, Elena calls for help and is terrified by Katherine's super-speed around the house before leaving. Upon her return, Damon Salvatore and Stefan Salvatore are left reeling after she's caused so much damage in so little time. At the mayor's wake at the Lockwood mansion, she engages in a small power play with Bonnie Bennett, claiming that it never ends well for Bennett Family. Bonnie attempts her Pain Infliction against vampires, but Katherine, a much older vampire than Bonnie is used to encountering, seems to have a certain amount of resistance to such spells.

Katherine claims to Stefan that she returned for him, and the two engage in light banter, Katherine playfully and Stefan suspiciously. Their conversation effectively ends when Stefan tells Katherine he hates her and in retaliation she skewers him with a metal rod. Later, Damon demand the truth after he and Katherine make out, and she confesses that she never loved him and that "it was always Stefan" that she loved.

Later, she visits Caroline Forbes in the hospital and tells her to give the Salvatores a message: "Game on." Then she smothers Caroline with a pillow, killing her with Damon's blood in her system. A few days later, Katherine appears in Caroline's bedroom and tells her not to be frightened, and that they were going to have so much fun together.

After blackmailing Caroline into distracting Elena, Katherine sets her sights on Stefan for the day. She gets an early start by manipulating his dreams, bringing him back to when he had escorted her to the Founder's Ball in 1864. In the dream, he notices that Damon has found someone to entertain himself with - Elena. Katherine then takes the dream to present day, where Elena and Damon are getting cozy at the Mystic Grill. Stefan wakes suddenly to find Elena asleep in his arms, but he quickly realizes it is actually Katherine.

Later, after he has locked Katherine up in the cellar and threatened her with vervain unless she tells the truth about her return, Stefan interrogates her and she reveals her deal in 1864 with George Lockwood, a werewolf. In exchange for the rare moonstone, Lockwood saved her from imprisonment in the tomb. Stefan points out that she betrayed all the other vampires, including her friend Pearl, just to fake her death, and Katherine seems to have no regrets about her past actions. She insists that she never compelled Stefan to love her, that his love for her was real, and she only compelled him not to fear her. After she escapes the interrogation, she finally meets her doppelgänger, Elena, face to face. In a final flashback to 1864, Katherine is ready to leave Mystic Falls, but falls back to kiss an unconscious Stefan one last time, promising they would be together again one day.

It is soon revealed that Katherine had set up Mason Lockwood's first kill in order to trigger his werewolf gene. She continues to manipulate him by seducing him and persuading him to find the moonstone from the Lockwood mansion. After Mason is killed, Katherine compels Jenna to stab herself as revenge on the Salvatore camp, and also compels Matt Donovan to pick a fight with Tyler and not stop until Tyler kills him. Katherine decides to retrieve the moonstone herself with the help of Lucy Bennett, a witch. She dances with Stefan and briefly tries for a diplomatic surrender, but when he refuses to give up the stone, she kills Aimee Bradley in the middle of the dance floor. Later, Caroline successfully lures Katherine into a room upstairs that Bonnie had put a spell on, preventing vampires from leaving it. Stuck in the room with Damon and Stefan, Katherine goads the brothers until they attack her.

Unfortunately, Lucy had cast a spell over Katherine and Elena so that whatever happened to Katherine would also happen to Elena. After learning of Bonnie's involvement, however, Lucy turns the tables on Katherine; after her debt to Katherine has been paid by getting her the moonstone, Lucy incapacitates her. Katherine awakes imprisoned in the tomb, where Damon says she should have been for a long time. As Damon closes the door of the tomb, Katherine screams that Elena is in danger and needs to be protected.

After learning from Rose about the existence of the Originals, Elena visits Katherine to ask her about her past. Katherine complies in exchange for incremental amounts of blood; he time in the tomb without sustenance has weakened her. Through flashbacks, Katherine reveals that she had borne a child before she was turned, and that she was the first Petrova doppelgänger. She explains that, as such, Klaus wanted to sacrifice her as part of a ritual to break a curse. Katherine recounts how she foiled Klaus' plan by tricking Rose into turning her, thus rendering her useless for the sacrifice. Now that another doppelgänger had appeared, the moment Klaus discovered Elena's existence he would find her for the sacrifice and attempt the ritual again.

When Stefan finally arrives searching for Elena, Katherine warns them that Klaus would not hesitate to kill all of the people Elena loves, just like Klaus had done to her. Stefan accuses her of tricking Elena, in a desperate attempt to get herself out of the tomb, but Katherine insists that the tomb is the safest place to be, as no vampire would want to enter for fear of being trapped. Later, alone once more, Katherine peruses the Petrova Family history that Elena had brought, tearing up over drawings of her parents.

In an attempt to get the moonstone from Katherine, Bonnie performs a spell that involves burning Stefan's picture of Katherine from 1864 and throwing the ashes on her, rendering her unconscious for a minute or two. Jeremy, in a valiant effort to spare Bonnie from overexerting her powers, ventures into the tomb alone and asks Katherine for the moonstone. Naturally she refuses, so he shoots a stake into her chest and, while she's distracted, throws the ashes into her face and incapacitates her. While she is unconscious, he enters the tomb, searches for and finds the moonstone, and tries to leave but Katherine revives and attacks him. When Stefan and Bonnie arrive, Katherine holds Jeremy hostage and demands that Bonnie open the tomb so that she can escape. When Bonnie fails, Katherine bites Jeremy but Stefan reacts by entering the tomb and throwing Jeremy out of it, now imprisoning himself along with Katherine.

Katherine is very pleased with herself for trapping Stefan with her. She enjoys planting dreams in his head while he sleeps, though later she does offer the useful advice of seeking out Isobel for information about Klaus. After Elena strikes a deal with Elijah, the warlock Jonas breaks the spell of the tomb, allowing vampires to leave it. Elijah allows Stefan to leave, but compels Katherine to stay inside.

When Damon visits Katherine in the tomb fishing for confirmation about how to kill an Original, she begs Damon not to kill Elijah, because then she would be stuck in the tomb forever. Later this is revealed to be a lie: rather, Katherine knew that killing the Original that had compelled her would actually release her from the compulsion. After they've staked Elijah, Damon finds Katherine in his shower, cheekily asking for a robe to borrow. She further surprises Damon by reaffirming her pledge to help him protect Elena. Katherine subsequently takes up residence with the Salvatore brothers, much to the displeasure of Elena.

Katherine repeatedly states that she will help them to deal with Klaus, and engages in research with the brothers. She is staked and nearly killed by Luka Martin when he infiltrates the mansion via astral projection in an attempt to release Elijah, but is rescued by Damon, who unwittingly burns Luka to death. When his father strikes out in a rage against Elena, Katherine tricks him into believing that she is Elena and kills him. Later, she flirts with Damon in bed, despite admitting to him that she knew the dagger would kill the vampire who used it, and, having to make a choice between Damon and Stefan in a deal with John and Isobel, she chose Stefan once again. Needless to say, Damon does not play along and asks Katherine to find another room to sleep in.

Despite insisting to Stefan and Damon that she's on their side when it comes to killing Klaus, Katherine reunites with Isobel, formulating a contingency plan in case things don't go well for the Salvatores. She helps Isobel kidnap Elena, but soon Isobel double-crosses her and the warlock Maddox incapacitates her, later delivering her to Klaus.

In The Last Dance, Klaus/Alaric compels her to tell him everything she knows, even coaxing out of her information she isn't sure about. He denies her request that he just kill her; he considers death to be a "kindness" after searching for her for over 500 years, and promises to draw out his punishment for at least half as long. After their conversation, Klaus/Alaric hands her a pocket knife and compels her to stab herself repeatedly until he returns. In Klaus, Katherine asks Klaus/Alaric why he would undo the curse in Mystic Falls knowing that a lot people will try to stop him.

Klaus/Alaric reveals to her that he must perform the ritual at the doppelgängers birthplace. Katherine remarks that she didn't know that was a requirement, to which Klaus/Alaric responds with the cruel reminder that, though she had fled before she could learn these details, Klaus did just fine finding her birthplace - and slaughtering her family. As Klaus/Alaric is leaving, he tells her she can't leave until he tells her to. Later, Damon and Andie Star go to Alaric's apartment to discover Katherine is alive. Damon tells Katherine he has vervain, which won't undo Klaus/Alaric's compulsion but will prevent further compulsion. Before he gives it to her, he demands to know why she double-crossed them with Isobel. She replies that she didn't think the others could stand a chance against Klaus and she was looking out for herself. Damon gives her the vervain and tells her she owes him - and he will collect. Later that night Katherine is drinking and dancing around the apartment until she hears Klaus/Alaric returning. He tells her Alaric's body is no longer useful. Irritated when Katherine tries to ply him with alcohol, Klaus/Alaric snatches the bottle away from her, throws it against the wall and compels her to sit down and shut up. Having taken the vervain, Katherine only pretends to submit to his compulsion. When Maddox returns with Greta Martin and Klaus' casket, they perform a spell to return Klaus to his true body. They open the casket and Katherine watches in horror as the real Klaus walks out.

In The Last Day, Damon goes to Alaric's apartment to collect his debt for giving her vervain. He asks Katherine where Klaus is keeping the werewolf. Katherine is reluctant to help out but reveals that Klaus has captured Caroline and Tyler. She is shocked to learn that Elena has vampire blood in her system and Damon warns her that this means she would have to compete with Elena for Stefan's love forever. Katherine reveals that Caroline and Tyler are being held in the tomb.

Klaus returns to Alaric's apartment and is immediately suspicious of Katherine. He compels her to tell him what she has been doing but, as she is taking vervain, she is able to lie. Still suspicious, he compels her to remove her daylight bracelet, walk to the window and stand in the sunlight. Katherine has to do it to keep up the ruse and screams in pain until Klaus relents, satisfied. Later that night, after Klaus returns to the apartment and tells Katherine that Elena is with Greta, Damon appears and tells Klaus that he rescued the werewolf and vampire and killed Maddox, thereby foiling his plan. Klaus has Katherine leave the room, then informs Damon of his backup plans. Katherine revives Damon with a blood bag (Klaus had knocked him out off-screen) and tells him that Klaus has gone to begin the ritual. She admits that she had to do something so Klaus wouldn't realize she was on vervain, and reveals that Klaus made her make a call as Elena to lure someone out, explaining that he needed another vampire. Damon asks why Klaus didn't use him as the vampire in the sacrifice. Apparently Klaus had said that Damon was as good as dead. She points out the ugly wound on his arm and asks what it is. He replies, "It's a werewolf bite."

In The Sun Also Rises, Damon shows Katherine his werewolf bite but decides to leave. She is hurt that after 145 years he is leaving without saying goodbye and tells him not to depart on bad terms. She insists that she didn't have a choice and had to lure Jenna for Klaus, adding that she chose her life over Jenna's. Damon observes that Katherine will survive all of this without a scratch. Katherine points out that she doesn't let love get in the way and Damon tells her to enjoy an eternity alone. He leaves to offer himself to Klaus, but Katherine insists that Klaus won't accept him as his blood is impure.

In As I Lay Dying, Damon has a flashback and remembers speaking to Katherine in the 1860s. In it, she asks if he will miss her while he is off fighting and he says he will, but points out that she will still have Stefan. Katherine asks if it is so wrong for her to want them both. However, Damon hallucinates that Elena has joined them. Elena tells him that Katherine was just toying with him and he could have walked away - he had a choice. Flashback-Katherine bids him to return quickly.

Stefan shows up at Alaric's apartment looking for Klaus and finds Katherine there, wondering why Klaus' compulsion hasn't worn off. He admits that they failed to kill him just before Klaus returns. She watches as Stefan tries to bargain with Klaus for the cure to a werewolf bite. Klaus calls Katherine over and bites her; she starts to panic, but Klaus immediately feeds her his blood, and the bite heals, revealing that Klaus' blood is the cure. Meanwhile, Damon suffers more hallucinations of Katherine, mixing the present with the past, thinking he is chasing her through some woods. He remembers begging Katherine to feed him her blood so they could be together forever. Back in the apartment, Klaus calls Katherine over and compels her to take his blood to Damon and to come right back. She leaves immediately, but Stefan, knowing that Katherine has been ingesting vervain, worries that she will never deliver the cure to Damon.

However, Katherine does follow through and appears at the eleventh hour, interrupting Elena's would-be final moments with Damon. She admits that she decided to deliver it because she owed Damon. Elena asks about Stefan, and Katherine informs them that Stefan has surrendered himself to Klaus in exchange for the cure. Before she leaves, and after taunting Elena about working two Salvatores at once, she adds that it's OK to love them both - she did, after all.

Season 3

Katherine makes her first appearance of the season in The End of the Affair, when she calls Damon and gives him information about Stefan's whereabouts. She declines to tell Damon where she is, but is later seen exiting a phone booth in Chicago. In Disturbing Behavior, she is still in Chicago and catches Stefan's attention outside of a boutique where Rebekah is trying on clothes. She fishes for information about Rebekah's necklace, which Klaus is looking for and which Stefan gave to Elena. She wants to know Stefan's plans, but he refuses to share them. Katherine warns him about plotting against Klaus, as well as dealing with Rebekah. She later saves him from Gloria's torture by stabbing the witch in the neck, and wants in on his plans if they involve taking down Klaus, but he turns her down again.

Towards the end of the episode, Katherine fools Bonnie into thinking she's Elena, and manages to steal Esther's Talisman. She shows up at the Boarding House with the necklace, proposing to Damon that they team up and get away from Mystic Falls to go on a little "road trip".

In The Reckoning, after they stop the car, Katherine reveals to Damon that she has kidnapped Jeremy. She needs Jeremy because he is able to communicate with ghosts, and he has a connection with Anna, one of the only people who knew anything about Mikael, a vampire who hunts vampires. Anna says Mikael is the only one who can kill Klaus for good, and he was entombed by a Abby Bennett the witch in the 1990s. Anna reluctantly gives them information about him, warning them that Mikael will kill all of them if awakened.

Katherine ignores her warning, and is able to locate his tomb with Jeremy's help. Katherine spends two days trying, unsuccessfully, to get Mikael to feed, and finally brings him a human and drips fresh blood into his mouth. Mikael opens his eyes, and, horrified, orders her to stop feeding him the blood. As he continues to lay in his coffin, still very weak, she begins to doubt his formidable reputation. She asks him whether he can kill Klaus or not, and Mikael answers affirmatively. He asks Katherine to remove the chains restraining him; after she does, he reveals that he does not feed on living things, and proceeds to attack and feed on her.

In Homecoming, Damon enlists Katherine in a plan to kill Klaus. She pretends to be Elena so that Elena won't be in danger when everything goes down. However, during the party, Klaus, thinking that she is Elena, reveals that in the event that Klaus is killed, the other Hybrids will kill Damon. Katherine then runs back to the Salvatore house, revives Stefan (whom Mikael and Damon had incapacitated to keep him away from the party) and tells him what Klaus said. She tries to convince him to care enough to stop Damon from killing Klaus, because regardless of what he decides, she is going back to see the plan through.

Back at the party, Mikael compels one of the hybrids to grab Katherine (pretending to be Elena) and threatens to kill her if Klaus does not leave the Lockwood house. Klaus, believing that Mikael is bluffing, says to go ahead. Mikael then stabs Katherine, who falls down apparently mortally wounded, right as Damon jumps Klaus. Much to Mikael's surprise, Katherine stands up, throws wolfsbane grenades at the approaching hybrids and flees the scene.

Later, she calls Damon to tell him he had a good plan and confirms Damon's assumption that she's already heading out of town. She hangs up with Damon and turns to Stefan, who is in the passenger seat. He asks Katherine why she, who has wanted Klaus dead for 500 years, would stop a plan to kill him just to save Damon. Katherine says she did it not just to save Damon, but also Stefan's humanity. He doesn't believe her, reminding her that she only cares about herself. Katherine tells him he knows that's not true, and that despite everything that had happened, she did love Stefan and Damon.

Katherine then says that humanity is a vampire's greatest weakness, and no matter how hard one tries to suppress it, it keeps trying to fight its way back in - and sometimes, she lets it. Stefan confesses that he doesn't want to let his humanity back in after everything he has done. Katherine says that he must, because she needs him to get angry enough at Klaus to do what she has planned next. She convinces him to steal the coffins that Klaus keeps his family in, before she herself puts as many miles as possible between her and Klaus.

Season 4

In We All Go a Little Mad Sometimes], Katherine appears to Elena through vivid hallucinations. She torments Elena, telling her they're both the same and that she deserves to die. She proceeds to tell Elena that now that she's a vampire, Stefan is going to hate her, too. Later, Elena finds herself walking to the Wickery Bridge with Connor on one side and Katherine on the other, asking her if she's ready to die yet and telling her she can't take back what she's done, that she's a monster who deserves to die.

In A View to a Kill, Jeremy mentions Katherine, saying, "We might as well look up Katherine Pierce and see if she wants some company in hiding, 'cause he (Klaus) will come after us!"

In Into the Wild, unknown to the viewers or characters, Katherine kills the Mysterious Attacker to save Jeremy.

In Down the Rabbit Hole, Katherine makes her dramatic return. Unseen by the characters or viewers, she kills Massak and presumably steals the headstone from him. Later, she confronts and attacks Elena in the caves, defeating her and switching clothes with her. As Vaughn is about to finish Jeremy off, "Elena" swoops in to save him. She is about to bite Vaughn and kill him when Jeremy reminds her of the Hunter's Curse; instead she just knocks Vaughn out. Katherine continues to pose as Elena while Jeremy begs her to heal Bonnie with her blood to save her, but "Elena" insists they must raise Silas and get the cure first. Growing impatient, Katherine reveals her identity and grabs Jeremy, slits his wrist, and puts it in Silas' mouth, causing Silas' eyes to open. To speed things up, Katherine bites Jeremy's neck and holds the wound over Silas' mouth. Silas gains enough strength to raise his hand and hold Jeremy's head in place, so Katherine grabs the now unguarded cure and flees.

While not physically appearing in Bring It On, Katherine did send the vampire Will to kill the werewolf Hayley, who was now no more than a liability, having served her sole purpose of telling Katherine where to find the cure and how to get it. Later on, Hayley reveals to Klaus that Katherine had successfully managed to avoid him for over 500 years because she had established a network of people who were willing to do anything for her, including tie up loose ends.

Katherine does not appear again until American Gothic, when Elena and Rebekah track her to a small town where she has compelled everyone to keep her presence there, among other things, a secret. However, Elena is able to glean information from the townsfolk, who are unaware that Katherine has a doppelgänger and believe that Elena is Katherine. Katherine spots Elena searching the town and ambushes her, but Rebekah quickly intervenes and reestablishes dominance. Rebekah and Elena bring Katherine to a diner to interrogate her, which she unwillingly endures with her usual snark. When Katherine mentions Jeremy, whose death she had caused, Elena remains indifferent and Katherine realizes that her descendant has abandoned her humanity. Rebekah attempts to compel Katherine to reveal where the cure is, but Katherine smiles and informs them that she's on vervain. However, she does reveal that she wants the cure in order to barter with Klaus for her freedom. When Elena finds out Katherine is supposed to be meeting someone named Elijah Mikaelson "EM", she exchanges clothing and accessories with Katherine and goes to the meeting in her place.

After Elena leaves, Katherine antagonizes Rebekah until the Stefan and Damon Salvatores arrive, demanding to know where Elena is. Katherine admits that Elena has unknowingly gone to meet Elijah, with whom she hints at having a sexual relationship. Rebekah tells Stefan where Elena is meeting "EM" and Katherine reluctantly agrees to take Rebekah and Damon to the cure.

Katherine takes Rebekah and Damon to a home she says is hers and, after opening a safe, claims that the cure has been stolen. They don't believe her, so Rebekah heads upstairs to search, leaving Damon alone with Katherine. He notices that the fish tank suspiciously has no fish in it, but only a large treasure chest. When he reaches into the tank, his hand gets burned - it is filled with vervain. Damon begins to attempt to scoop out the chest with a net when Katherine shoves his head into the vervain for several seconds, then sends him howling in pain to the floor. She secures the chest herself and almost escapes out the front door, but Rebekah reappears and blocks her way. Katherine tosses the cure away from herself, distracting Rebekah long enough so that she can escape.

While Elijah and Elena discuss the foolishness men who believe the innocent girls they (Elijah and the Salvatores) fell in love with still exist within who Katherine and Elena are now, Katherine appears suddenly and snaps Elena's neck. Elijah kneels by Elena's lifeless body and confronts Katherine about her killing Jeremy and feeling nothing for Elena despite their similarly tragic fates. Katherine says she didn't enjoy killing Jeremy, but that doing so was necessary to survive. Elijah wonders aloud if that's what he is to her—a means to survive. She protests, insisting that she loves him, but Elijah cannot be persuaded. She makes a last-ditch effort by reminding him that she can't broker a deal with Klaus without his help, but this appears to hurt the situation more than it helps, and Elijah leaves her.

Katherine arrives, alone, at the home of the woman Elena and Rebekah had first talked to when they got to town and retrieves her "package" - the real cure and the key to securing her freedom. Later, Katherine confronts Elijah on the street and tells him that he was right: she's told so many lies to survive for so long, she's beginning to believe them herself. She admits that she doesn't remember who she was when they met, but that she'd like to find out. Katherine explains that she could use the cure to make Klaus mortal and kill him, but this would mean losing Elijah, a consequence she's not willing to accept. Elijah, moved by Katherine's speech, still resists temptation and raises concerns about Katherine's track record for deceiving men. Katherine responds by taking his hand and placing the cure in it, saying she wants him to trust her like she's now trusting him, and that he must decide what happens next, with both the cure and their relationship.

Katherine does not appear in Pictures of You, but she does leave Klaus a letter:

I hear Elijah has refused you the cure and in return, you have refused me my freedom. Shame on you both. But while you boys sort out your problems, I have one last thing to offer you. I've caught wind that there is a witch in New Orleans named Jane-Anne Deveraux plotting a move against you. Hunt her down. What she has to say will rattle you so deeply to your core that chasing little old me will be the least of your concerns. It's been a fun five centuries, Klaus, but I've worn down too many good heels running from you.
Love and hate,

In The Originals, Katherine returns to Mystic Falls after Klaus' departure to New Orleans. She casually strolls into the Salvatore boarding house and tells Stefan and Damon that Hayley was exactly what they needed to get rid of Klaus for good. Later, she shows up at Rebekah's house uninvited and eavesdrops on Rebekah's phone call with Elijah. She insists that she and Klaus are the same in that they are driven by their loneliness, and Klaus won't be able to walk away from his new situation with Hayley.

After Rebekah refuses to follow Klaus and Elijah to New Orleans, Katherine begs Elijah to stay with her so they can make a life of their own and let Klaus deal with his own business. Elijah kisses her on the forehead and says, "Goodbye, Katerina".

In She's Come Undone, Katherine meets with Bonnie, who wants Silas' headstone which Katherine stole along with the cure. Katherine, reluctant to give up her potential leverage, asks Bonnie how she could benefit from handing it over, but Bonnie just vaguely insists that she would make it worth Katherine's while.

Later, she arrives at the Salvatore boarding house at the brothers' request; they want Katherine's help with bringing back Elena's humanity, and Katherine is more than happy to torture her doppelgänger. When she enters the house, she taunts Rebekah and Matt before heading down to the cell where Elena is locked up. Katherine pulls Elena out of the vault and makes a snarky remark about checking to see if Elena still has a heart before she plunges her hand in Elena's chest. Katherine interrogates her, asking about what transpired between Elena and Elijah in Willoughby; Katherine clearly believes that whatever Elena said turned Elijah against her. In response, Elena goads Katherine about running from Klaus for so long, calls her a self-obsessed maniac and cruelly wonders aloud why anyone would want to be with "damaged goods" like her. Katherine retaliates by grabbing Elena's neck and admits that she's done terrible things to survive, but instead of turning off her humanity, she dealt with it. She adds that Elena wouldn't last a week as a vampire without everyone fawning over her before she locks her in the vault again. After a moment, she decides that seeing Elena go on a rampage would be more entertaining and unlocks the vault, leaving it open for Elena to escape.

She returns to the main level of the house and pours herself a few successive glasses of bourbon while talking to Damon. She taunts him by predicting that Elena will rush back to Stefan when she gets her humanity back, calling this the tragedy of Damon: he never gets the girl. At that moment, Stefan shows up and reveals that Elena has escaped. Katherine feigns carelessness before admitting that she would derive more pleasure from seeing Elena continue her downward spiral than if she managed to start recovering from it.

Bonnie sets up another meeting with Katherine, who has figured out that Bonnie needs the headstone because it contains Qetsiyah's blood. Having the headstone would give Bonnie the power to drop the veil to The Other Side whenever she chooses, instead of having to wait to channel the power of the full moon. Katherine asks again what is in it for her, and Bonnie sweetens the deal by promising that once the veil is dropped, she'll find out from Qetsiyah how she made Silas invulnerable to any weapon, and in turn Bonnie will share the secret with Katherine. With the prospect of finally having true freedom from Klaus in her sights, Katherine agrees to the deal.

In The Walking Dead, Katherine met Bonnie in the woods where we learned that Bonnie wanted to charge all three points of the Expression Triangle (where the massacres had taken place) and channel the mystical energy from Silas' tombstone. That would drop the veil inside the points of the Triangle just long enough to get what she needs—which is to contact Qetsiyah and find out how she put Silas down. Katherine tried to walk away, but Bonnie had linked them so that Katherine was on an invisible leash and whatever happened to one of them happened to the other. Bonnie couldn't have Silas getting inside Katherine's head and finding out Bonnie could do the spell whenever she wanted. She went with Bonnie to the other two places where the massacres took place and then they went to a cave which is located in the center of the expression triangle. Katherine heard someone coming, so Bonnie gave her more leash so she could go stop them. It was Elena, who managed to stake Katherine in the stomach. Bonnie felt it, too, and bled. Elena could've finished Katherine off, but Stefan had heard from Bonnie about the link, so he stopped Elena. Katherine bolted.

In Graduation, Katherine confronts Bonnie, demanding the immortality that she was promised in return for the tombstone containing Qetsiyah's calcified blood. When Bonnie informs her that she is out of luck since Bonnie was unable to contact Qetsiyah about the spell, Katherine gets angry and vengeful, and threatens to kill Elena, who she feels has a better life than she deserves. Bonnie threatens her right back, but is distracted by other students arriving for graduation, giving Katherine the opportunity to slink away. When Elena arrives back at the school looking for Bonnie and Jeremy before the veil is put back up, she is ambushed by Katherine, who throws her against lockers and kicks her around. After a few nasty comments from Katherine, Elena gets riled up and begins to fight back with almost equal measure. Katherine gains the upper hand, and is about to rip out Elena's heart when Elena pulls the cure out of her pocket and shoves it into Katherine's mouth. She forces Katherine's jaw shut to break open the vial as she struggles to get free from Katherine's grip. After a few moments Katherine falls unconscious next to Elena, who wishes her a "happy, human life."

It is unknown what effect the cure will have on Katherine, though it is assumed that she will now be human. However, any potential side effects of taking the cure have not yet been revealed.

Season 5

In I Know What You Did Last Summer, Katherine is first seen upon a street in Mystic Falls, paranoid and disheveled. She goes to the Salvatore house for help and she talks with Damon. She begs him for protection now that she is human, weak, slow and unable to protect herself against her numerous enemies, to which Damon reluctantly agrees.

Whilst she is taking a bath in Damon's tub, Silas imitating Stefan shows up suddenly. They flirt and when they are about to kiss Silas grabs her neck, attempting to drown her and she grabs a razor and cuts his face before running downstairs. Damon stops her, throws her to Jeremy and tells him to take her far away, however not to tell him where he is going. Damon stays in the house with Silas, and Silas reveals the whole truth about Stefan suffering "like he has".

Silas asks him to return Katherine for his brother, Damon makes up his mind and immediately calls Jeremy and tells him to return to the house. As soon as Jeremy turns around, Katherine knows what is happening and demands Jeremy to stop the car, however when he tells her to shut up, she tries to escape causing an accident where she and Jeremy are seriously injured by crashing into a post. She limps from the car, spotting a barely conscious Jeremy who asks for her help, she ignores him and hobbles away, leaving him dying in the middle of the road.

In True Lies, after leaving Jeremy to die, Katherine flees into the woods. The morning after, she's leaving the woods and getting sick. Katherine walks to the road where she stops a car. Katherine thanks the woman for stopping and the woman tells her she looks just like Elena, but Katherine insists she's much prettier than Elena. The woman maces Katherine, and as Katherine shrieks in pain, the woman pulls out her phone to text Silas. Katherine angrily tackles the woman, smashes her phone, and knocks out the woman, and then Katherine shrieks again in pain from punching the woman, since she's used to having her super strength and not feeling pain. A gun loading is heard behind Katherine and she looks over to Matt, who tells her it looked like it hurt, but his gun will be more effective. Matt and Jeremy take Katherine and keep her out of sight since Silas has the whole town hunting her. They give her some clothes since she was in a robe and Matt begins to tie her up. Katherine compliments Matt on his eyes, telling him they made her soft and that she should have ripped his head off when she had the chance.

She asks them if the rope is really necessary and Jeremy reminds her that she almost got the two of them killed and left him to die. Katherine says she was doing what she always does anything to survive. She also tells them she's been through this a thousand times: she's the leverage, the one thing everyone wants. She says she's now like the moonstone, as Matt settles her in the truck. Later, they stop at the gas station where Katherine says she needs to get out of the car, but Jeremy tells her no. Katherine then complains that she needs to go to the bathroom and should go like a lady. Jeremy unties her and tells her to hurry, Katherine tells him that she's getting sick and is coughing up green stuff and tells him to get her something for it, Jeremy tells her he can't so she begs Matt to do it. As Matt gets medicine for her and Jeremy gets gas for the truck, Katherine goes to the bathroom and sees an opportunity to run. When the clerk in the store sees Katherine, he begins to call Silas as Katherine runs off. Jeremy catches her and tells her to stop running and takes her back to the truck. That night, Jeremy, Matt, and Katherine create a bonfire. She sees a shotgun, but Jeremy tells her not to think about it. Katherine replies that she doesn't know how to use a gun because she didn't need one and that she was much deadlier. Katherine then complains that, after surviving childbirth, the death of her entire family, and running from Klaus, she's upset about being defeated from a sinus infection. After Silas stabs Jeremy (by stabbing himself first), Katherine returns and shoots Silas.

In Original Sin, Katherine decides to accompany Damon and Elena in search of Stefan, after having the same dream as Elena with the possible whereabouts of Stefan. She says that Stefan is also important to her and she jokes in all the way to Damon and Elena about their relationship.

When they get to the place where the doppelgängers saw Stefan, Katherine is asleep in the car. Damon and Elena decide to enter and leave her there. After Katherine enters and meets Nadia Petrova, Katherine flees until she meets again with Elena in the forest. They have a conversation and Nadia appears, snaps Elena's neck and takes Katherine. When they are about to escape, Silas arrives. Nadia tells him that she isn't going to deliver Katherine. Silas enters in her head and tries to force her to commit suicide, when Nadia is about to do it, Silas falls to the ground in pain and they flee.

Katherine is rummaging in Nadia's stuff when she enters the room. Nadia is conversing with Katherine when Silas calls her and says she must deliver Katherine. Katherine takes the phone asking what he wants with her and Silas replies: "The cure still exists, and I still want it. It's just running through your veins right now. Your blood is the cure, Katherine."

In Monster's Ball, Nadia and Katherine are still at the Motel, hiding from Silas when Nadia gets a call from him. He tells her he wants Katherine, but Nadia refuses to give her up. Nadia continues to tease him about his inability to use his powers, and Silas tells her he can track them through cell phone tracking. Nadia quickly hangs up on him and tries to take Katherine away. Katherine asks her why she doesn't just hand her over to Silas so he can just have his "little sip" of her blood. Nadia tells her that Silas needs every last drop of blood in her body, which will kill her.

Later on, Nadia and Katherine are eating lunch at a diner and Nadia tells her that she's been tailing her for 500 years and that she wants answers, and if she gets them, she'll let Katherine go. Katherine agrees and Nadia tells her that in 1864, she heard about the vampire round up in Mystic Falls, when Katherine sold out her other friends. Katherine tells her about the many horrible things she's done and Nadia asks her if she remembers ripping a mother away from her daughter. Katherine doesn't recall this and Nadia tells her that Katherine killed her mother in Paris in 1645, and that she has been spending the last 500 years hunting Katherine down for revenge. Katherine realizes that Nadia does not plan on letting her go. Nadia tells her it's time to leave and Katherine seizes the opportunity to grab a nearby cane and stab Nadia with it in the chest before running off.

Katherine later finds Nadia in an alleyway, trying to get the cane out of her chest without touching her heart and Nadia asks her why she didn't kill her. Katherine says she knows Nadia's story about her mother was false. Nadia says it was a test and that Katherine failed. She says she wanted to get under Katherine's skin and she succeeded. Katherine asks her what game she is playing and Nadia tells her that Katherine really did kill her mother, but it was not in Paris but in England on April 6, 1492. She says how her mother was exiled by her family 2 years earlier and how Katherine put her mother's neck in a noose and threw her off a chair, snapping her neck, the same way Katherine died when she was human. Katherine is confused and Nadia reveals that her name is Nadia Petrova, and that Katherine is her mother. She is the child that was born out of wedlock and was taken away from Katherine by her father when she was human. Katherine is shocked to learn this. Later on, Nadia wakes up to find the cane removed from her chest and looks up to see Katherine, and tells her she is a fool for not running because Silas will find her. Katherine says she isn't worried, she is good at running and that Silas doesn't need her until he figures out how to destroy the Other Side because if he dies as a witch he will be stuck in "supernatural purgatory".

Katherine says she has had a question bugging her for 500 years. She asks Nadia where she was in 1498. Nadia says she cannot remember because she was only 8 years old, and Katherine tells her that by then she had escaped Klaus and went back to Bulgaria. She tells Nadia she searched every village, every cottage looking for her and she couldn't find her. She says she went back for her, and that it's nice to meet her. Nadia begins crying and smiles before accepting a cup of tea from Katherine.

When Katherine arrives at the Salvatore mansion, lifeless Silas on a couch nearby, she's ecstatic in knowing that she may have toppled the all mighty Silas and escaped death for good. But Damon has other plans. After Katherine unsuccessfully pleads for him to spare her (she doesn't want to die after all), Damon shoves her neck down Silas' throat, draining her of her cure-laced blood. Moments later, Katherine suddenly awakens with her heart still thumping: "Am I in hell?"

In Handle with Care, Katherine celebrates the fact that she hasn't died by indulging in food when she notices that her hair is starting to gray. She then dyes her hair and moves into Elena and Caroline's dorm room and pretend to be her but Caroline realizes that she is Katherine then she takes her neck. Katherine says that she needs a place to live, Caroline at first says no but Katherine tells her that she can help with the Dr. Maxfield and Caroline accepts.

Later, the professor Maxfield in his laboratory, is conducting experiments with vampire blood, Caroline appears and Katherine takes the opportunity to inject a substance into his neck, the professor faints on the floor. Caroline and Katherine planned to drain the vervain in his system to compel him to tell them everything he knows about vampires, Katherine takes over and begins to drain blood from the professor. he tells them that the secret society planned to invite Elena to belong to the group but for his suspicions that she was a vampire, they desisted. Katherine then takes the decision to impersonate Elena and Caroline stays with the professor.

She later attends a gathering at Whitmore House posing as Elena to make people believe that Elena is human, she meets Aaron and begins to ask him questions about the secret society but Aaron seems to have no idea what she's talking about. When they are talking, she loses her tooth while eating the food.

Katherine then suspects that she may be dying and goes to Dr. Maxfield for help. She tells him the truth that Elena is her doppelgänger and tells him that he has to help her to not die.

In Death and the Maiden, Katherine is in the laboratory of Dr. Maxfield asking him to help prevent her aging but he tells her that she were turned into a vampire over 500 years ago and now that she is human the time is catching up with her. He says that he can't do anything to stop it and that if it continues at this rate, she has a few months of life. He leaves and Katherine is very frightened by that.

Later, Caroline is at Whitmore College and she meets Nadia Petrova, they are talking and then Katherine comes, Nadia tries to tell Caroline that Katherine is her mother, but Katherine interrupts her and doesn't permit, Caroline leaves and they are left alone. Nadia wants to know the reason for her abandonment again but Katherine says that she never abandoned her, she say that Nadia was snatched out of her arms at birth because her father thought she was a knocked-up and second of all, that it's been 500 years and that she isn't required have to do the whole mother-daughter bonding thing.

Caroline interrupts the conversation between Nadia and Katherine and takes Katherine to the Salvatore Mansion, since Qetsiyah need her to perform the spell to the resurrection of Bonnie.

Katherine helps with Qetsiyah's spell but exchange for help with the issue of aging, Qetiyah accepts make a spell to stop it but after she resurrects Bonnie, Katherine agrees. Katherine, Amara and Elena are ready to perform the spell. They have to give some of their doppelgänger blood to do the spell. Qetsiyah cuts their hands and put their blood on Bonnie's grimoire, when they are about to complete the spell, they are interrupted by Silas. " When Katherine is trying to clean her blood after being cut by Qetsiyah on the hand, Caroline offers her blood to cure her but Katherine can't drink vampire's blood. After Katherine finds Qetsiyah alone in the mansion and she says it's time to do the spell, Qetsiyah tells her that she not going to help her and Katherine realizes that Qetsiyah is dying, she screams for help but Qetsiyah dies in her arms.

Later in the college Caroline is preparing her room for Bonnie too come back to life. Then Katherine arrives and understands that she has to go. She looks for her bag but can't find it. Nadia appears with her bag and tells Katherine that she will travel to Prague and she wants Katherine to come with her. Katherine says that it's all a fantasy. She would rather rip her own heart out than do more mother-daughter bonding with Nadia. Now that she is human, it wouldn't really be that easy. She says that she doesn't want to know her. Nadia Petrova is very sad about that and then Katherine says that she's never going to see her again. Katherine leaves the room.

In Dead Man on Campus, Katherine was the one to help Matt with his problem. She explained him to what Travelers are- they're a faction of witches that heavily believe in the spirit world. What they did to Matt was attach themselves onto his spirit like a parasite. Lucky for Matt, Katherine also happens to know who else can help him out, her daughter.

Katherine needs Stefan's help as part of her plan with Matt. After sweet talking and then moving onto guilt tripping, when the first didn't work, she got him to agree. He should have waited until she told him the whole plan because he sure is shocked to be formally introduced to Nadia of all people.

Nadia, Katherine, and Stefan are waiting in one of the store rooms when Matt comes in. Nadia calls forth her boyfriend out of Matt so Katherine can demand answers. Nadia through they're only mission was to kill Silas when that was just half of what Gregor came to Mystic Falls to do. He was sent to Kill Katherine. She has a dagger they want. It's one of the few things that can truly kill a spirit user. It seems she never had a liking for Travelers. Why? Well she believes they're all judgmental hypocrites. She should know, her father was one. Then kills Gregor. Nadia looked slightly upset with her mother.

Katherine hates running. She's done before and it's why she left behind a letter for Nadia explaining why she wanted to kill herself. Stefan saw it and saved Katherine from plummeting to death. She told him she was dying of old age, that the cure had somehow sped up the process. He told her this wasn't the way. Not for the Katherine Pierce. And then he walked away and she smiled.

In The Cell, Stefan was keeping a close eye on Katherine after the suicide attempt. She was writing in a diary at his request because he's worried she will try to kill herself again. But Katherine was just as concerned about him since she overheard some of his PTSD. Stefan didn't want to talk about it, but Katherine had already invited Caroline over to help.

Katherine tells Caroline that the therapy that she found in a textbook didn't work. Stefan was still freaking out and Katherine was questioning whether or not Caroline and Stefan had ever hooked up, Caroline answer that they are just friend and Katherine say that her loss because he's great in bed. Katherine pointed out that Stefan is the hero of the story and it can't be himself that he needs to save.

Her solution was to get into the safe with Stefan. He pointed out it was dangerous and she reminded him that she was dying anyway so it didn't matter if he ate her. Stefan started freaking out and getting upset and Katherine continued to talk him. She suggested that what he was really upset about was Damon and Elena and that he wanted to run away and never come back, but he kept finding excuses not to. She believes his trauma is because he'd rather experience the physical pain than the emotional pain.

To further prove her point, Katherine exposed her neck to Stefan. He got his vampire face on, but her words were getting through to him. They kept getting closer and it seemed like they were going to kiss and that was when Caroline felt the need to open the box because she thought it was too quiet.

Stefan is alone in the room and Katherine goes to see what he's up to. She helps him straighten up. Stefan tells her that she was right he does need to move on. They kind of drift towards each other. Katherine caresses his chest and then Stefan kisses her.

In Fifty Shades of Grayson, Katherine wakes up next to Stefan in bed. She leans over to cuddle when she notices gray hairs on the bed. She frantically covers herself with a sheet and leaves the room as Stefan looks on amused.

In the woods, Matt is helping Katherine to stay in shape. After some playful banter, Katherine worries when she can't hear what Matt is saying. Nadia arrives with the suicide note that Stefan gave to her. Nadia then slaps Katherine across the face and says that's for trying to "leave" without saying goodbye. In the Salvatore kitchen, Katherine ask Nadia if she's worthy of forgiveness. Nadia thinks that she is worthy and has been thinking about a plan to keep her mother alive.

Nadia suggests that Katherine try spirit possession. Since Katherine's father was a witch from the coven of the Traveler then technically Katherine is a Traveler witch too, meaning that she could use the spell to live in someone else's body. After Katherine says that Stefan prefers her in her current body, Nadia realizes that Katherine's question about forgiveness was in regards to Stefan and not her. Nadia angrily tells her mother to kill herself and see if anybody misses her.

Later, Katherine is looking at herself in the mirror when Stefan appears. She brings up their night of passion but Stefan says they got swept up in the moment and he can't just forget the last 147 years. Katherine asks what she has to do to get redemption and Stefan says one night isn't enough to erase her history. Katherine responds that either one night or an eternity and he still won't look at her like he looks at Elena. As Katherine begins to leave, Stefan stops her and clutches her hand. He says that he's sorry that she's dying and she replies that she is too.

Katherine calls Nadia and wants her to resume the plan of switching bodies. As they're talking, Katherine begins to have chest pains and doesn't answer Nadia back. As Nadia calls at her, she suffers a heart attack and falls down the stairs.

Katherine is dying in 500 Years of Solitude. The episode starts in earnest in a flashback. Bulgaria. A pregnant, human Katherine is having the contractions of childbirth. The baby is born, and Katherine is told that it is a girl, and begs to see her baby as they take her away. Katherine's father tells her that the baby will be better for it, and Katherine cries on her mother's shoulder. Katherine cries because they won't let her even hold her baby. She attempts to get up and grab her baby from her father, but her mom stops her, and Katherine cries some more. Stefan explains that the doctors think that Katherine had a heart attack. Nadia says that Katherine won't die of a heart attack. Stefan tells Nadia that Katherine is dying. He's compelled the doctors to let him take her home so she'll be comfortable.

Upstairs, Katherine asks Stefan if they're talking about her. Stefan says that they're "reminiscing" trying to gloss it over a bit for her. She says that she probably deserves it. While they're talking, she's looking at her hands and asks him if her hand looks wrinkled to him. He says it looks fine. Katherine tells him that if she "starts to sag. Anywhere," that he's to slit her carotid artery. Stefan accuses her of being vain, and she says that she'd rather go glamorous. Then, she's convinced that she sees an age spot on her hand, and Stefan tells her it isn't one and holds her hand. Katherine asks Stefan why he's being nice to her. He says that since she's dying, he can "muster" some compassion for her.

Katherine is not only dying but plagued by visions that have haunted her for her entire life. Her daughter gets ripped from her arms and Klaus murders her entire family. Damon returns to his more evil ways by trying to kill her and settling for taunting her psychically. Katherine is haunted by her past mistakes and it only gets worse as Damon manipulates her mind. She revisits the first time she ever saw Stefan and realizes that the doppelgänger connection might be truer than she thought.

Jenna reminds Katherine of how Katherine compelled her to stab herself in the stomach, and Damon appears in her place and reminds Katherine of how he had to compel Jenna to believe that she has just walked into the knife. Then Uncle John is there, "Hello fingers. Goodbye fingers." And then Elijah is where John was, sitting on the bed next to Katherine. She reaches up to touch his face, and then its Damon again. Damon tells her that no one is coming to say goodbye, because no one cares. Nadia has sneaked into the room behind him, snaps his neck, and says that she cares.

Nadia, Mia, and Katherine are discussing the words to the spell that have to be spoken for Katherine to jump into Nadia's body. Nadia wants her to repeat the spell, but Katherine won't. Finally, Katherine asks for a moment alone with her daughter. Katherine tells Nadia that letting her father take baby Nadia away from her is her biggest regret in life. She should have fought harder for her. She says that she spent the next 500 years making sure that she didn't make that mistake again. She says she's had a long life and finally got to know her "beautiful daughter." Katherine tells Nadia that she has spent the last few centuries searching, and Katherine doesn't want that life for her. She wants her to live. Damon has regained consciousness on the floor, but he doesn't let on. His disbelief at this conversation is pretty evident on his face. Katherine says that she's made selfish decisions all her life, this is just another one. Nadia gets mad and says that she won't sit by Katherine's side just to watch her die and storms out. Katherine stabs herself with another does of sedative and her eyes close.

Stefan sits down on the bed. Katherine says something about how these drugs she's on are "hard core." Stefan tells her to close her eyes, that he's come to say goodbye. Katherine says that she doesn't want to, because she wants to see him. He tells her that she will, and they go into her memory/dream thing of coming home and finding her family dead. He asks her if this is really the memory she wants to revisit. She says that it was the worst day of her life, and that Damon told her it was all her fault and that she deserves it. She says that she thinks Damon was right, she doesn't even deserve to be loved. Stefan disagrees and asks her to open her mind to him. Stefan takes away all the blood and gore of the scene, and all the bodies and then leads her to a crib, with a crying baby in it. We're led to believe that it's baby Nadia laying there. Stefan tells her that she's a 17-year-old girl and none of this is her fault. The baby cries again, and Katherine goes to the crib. There's a bright white light, and Katherine seems to go into it.

Stefan says, aloud, "Goodbye, Katherine" and Elena walks in and asks if she's gone. Stefan tells her that not yet, but she won't open her eyes again.

She dies for a second but refuses to go and literally makes her own heart beat again. Elena is standing over her newly conscious body and gives Katherine her heartfelt and sweet forgiveness. Katherine convinces her, and the audience that she's ready to die. Then grabs Elena and does the traveler spell to steal her body. The episode ends with Katherine impersonating Elena.

In The Devil Inside, she fights with Elena over her body. She needs her corpse to possess Elena's completely but doesn't know where it is. She compels Matt to find out facts about Elena and tries to convince everyone that she is Elena. Nadia is going to find out where her mother's body is and needs to leave her alone so she traps her to the bed just in case Elena fights and breaks through. Elena almost breaks free, but it is too late as Nadia is already back and pushes her aside so Katherine gains the control again.

As others are already worried about Elena, Katherine goes to the Matt's party in order to find information about her body and to be less suspicious about Elena's solitude. She talks with Stefan pretending to be Elena and asks him if he is heartbroken over Katherine's death and is upset that he is not. She asks him if they should have funeral or at least some flowers as she tries to find out about where her corpse is and at the same time hopes that Stefan would feel sorry for her death. Stefan reveals to her that Damon put her body to the place it "should have been long time ago". Katherine figures it means the tomb where Damon put her before, to punish her from 146 years of wasted waiting as she was not there.

She informs Nadia and they find her body and start ritual to make Elena's body hers but Elena breaks through and intervenes, hurting Mia who is casting the spell. Elena then runs off, but Katherine has changed the password so she can't call for help. Elena runs to Damon but is too late. As Elena didn't kill Mia she ends the spell and Katherine takes her body over. Katherine takes now permanent control over her body. Damon tries to fix thing between him and Elena, but as Katherine has control she breaks up with him. Katherine decides to stay in Mystic Falls to win back Stefan.

In Total Eclipse of the Heart, Katherine enjoys her life as Elena. She keeps Nadia close to Matt so she could find out all she needs about Elena and she is devoted to win Stefan back. She is trying to find a way to make his way closer to him and when Stefan calls her and wants to talk, she invites him to the Bitter Ball. They share a dance and she tries to convince him that she has given up on Damon and says that she doesn't like the person she has become with Damon and asks if Stefan does. When Caroline pulls her aside and tells her that she should slow down with Stefan she begins to worry that Caroline might have feelings for him. When she returns to Stefan she sees that Damon has kidnapped Jeremy, she leaves to call Nadia and asks her to find out what would Elena do in this situation and also ask Matt if Caroline has feelings for Stefan. She is very displeased to find out that Elena would do anything to save her brother, because Jeremy's death would be very convenient for her. In need not to break her cover has Elena, she begs Stefan to help her save Jeremy and tells him where he is.

They find Enzo with Jeremy and while Stefan is fighting Enzo, she more like pretends to help Jeremy than is really helping. When the encounter is over she asks Stefan about Aaron hoping that it will give her more reasons to apparently give up on him. She asks why did Stefan hide this fact about them and says that they should be honest with each other. Stefan tells her that he used to wish that Damon would mess up so badly, that she (Elena) would give on him, but as he saw that Damon was always there for her, he begun to like the person his brother has become and he doesn't want to lose him. Katherine takes the opportunity and promises to him that she will help him get Damon back, but makes it clear that she is doing it only for Stefan.

In No Exit, Katherine is first seen when she is studying with Stefan as she hopes to win him back as Elena. When Caroline visits Stefan and receives call from Tyler who informs Caroline that Nadia is compelling Matt, who is now missing, she starts to worry and calls Nadia, and tells her to kill Matt if he is danger to her secret. When Stefan decides to go after Damon, she offers to go with him so she could spend more time alone with Stefan. When they stop to tank, she uses opportunity to break his car and make herself dirty, so they could find hotel and get the room and shower, while they are waiting for car to be repaired. When Stefan is getting shower she answers Enzo's call who asks for their help, since he is trapped with Damon and hopes they could save them, before Damon kills him or he is forced to kill him. Katherine doesn't rush to tell this information to Stefan and instead of it she focuses on seducing Stefan. They kiss, but Stefan breaks it and tells her that it is wrong, since she just broke up with Damon. While Stefan leaves her alone she calls Nadia and asks who does she thin Stefan loves more: Damon or Elena, and reveals to her that she hopes that if she gets Damon to feed on her it would leave Stefan no choice, but to kill him to save her. When They find Damon, she steps into the house and pretends that she loves him and then cuts herself in front on him, forcing him to fight his urge to feed on her because he loves her. When Damon loses control and feeds on her she kicks the stake in front of Stefan and tells him that Damon is killing her, essentially asking him to kill Damon to save herself. Her plan backfires, when Stefan doesn't kill him, but cut's himself asking Damon to feed on him instead. Later she meets crusty Nadia, and tries to celebrate her good mood about her success with Stefan and her disappointment that Damon is still alive, but then she finds out that Nadia got bitten by Tyler and she is dying.

In Gone Girl, Katherine told Nadia she couldn't ask Klaus for his blood because he wouldn't help her anyway. Instead, she'd called Wes, who allegedly was willing to study Nadia's blood and create the antidote. He took some blood, and Katherine vowed to be a better mother, which meant saving her daughter's life. Caroline called Katherine and tried to get her to come help set up for a surprise birthday party for Bonnie but Katherine said she had to make arrangements for Aaron's funeral, which trumps a birthday. Exhausted anchor Bonnie tried to get her to meet her for coffee, but Katherine said she was at the spa buying Bonnie a gift certificate for her birthday. Katherine wondered why they were being so clingy. She phoned Damon, who told her to come on over and talk about what happened at the farmhouse. Katherine knew Damon would never put Elena in that danger again, so they must know she's Katherine.

Katherine takes Nadia to the church and tells her that they will leave once she is better. When looking for Wes, she found him dead. She then got a call from Stefan, letting her know that he has Nadia. Katherine stormed in the Salvatore Boarding House and said she was there to see her daughter. As Nadia took her last breaths, she said, "My mother's name is Katherine. I'm looking for her." I teared up. Katherine told her she found her, she's right there. Nadia said her mother's a liar, a murderer, she manipulates, and she betrays, and she'd do anything to survive. Nadia just kept saying she's looking for her mother. Katherine wanted to show her what her life should have been like. She said they had a little cottage. It was an ordinary summer day. Nadia had built a fort that she would show her mother in the morning. Katherine told her good night and to sleep well. And then Nadia died. "Your mother loves you," Katherine said, with a tear falling down her face.

As Katherine struggles with the realization that her daughter is gone for good, Nadia's ghosts appears before them all and looks on with great sorrow as her mom utters the exact phrase she's always longed to hear. She seems ready to move on but also upset at the sight of her mom grieving. 'Anchor" Bonnie, who is overcome with compassion, extends her hand and Nadia takes a hold of it and enters the Other Side. Suddenly, Katherine is left on her own and it's time to pay the piper. She kisses her daughter goodbye, closes her eyes, and covers her body. Then she stands up resolutely and…tries to make a dash for it, unfortunately for her, Damon's on the other side, blocking the exit. "Hello, Katherine. "Did you really think I'd miss this?" Realizing she's been beaten at her own game, Katherine concedes. "So who's got the knife? Which one of you gets to kill the elusive Katherine Pierce once and for all?" Uncomfortable silence falls over the room and you can almost hear crickets. Katherine, annoyed that they're being cowards. She decides to have her fun while she can and gets the party started by dishing out something called a reality check: she changed all their lives for the better, whether they care to admit it or not.

Just as she confesses her affection for the younger Salvatore, Stefan stabs her with the Traveler knife. "I guess this is how our love story ends," she gasps, her voice ridden with hurt. She collapses onto the floor, right next to daughter's body. Before going over to the Other Side, Katherine fills Bonnie in on yet another secret: she left Elena the worst parting gift ever. Apparently Katherine didn't like being forced to choose between running or spending time with her ailing daughter. "Katherine Pierce wasn't about to go gentle," she states. And what does Katherine hate more than anything else? The idea of cute and sweet little Elena winning. So while at Dr. Wes' decrepit lab, Katherine finds the syringe containing Nadia's blood sample and also a tape recorder in which Dr. Wes revealed that the werewolf toxin would be useful in making the vampire virus contagious, and freaking injects into Elena's body. Katherine could care less about the repercussions of her actions. If she can't have Stefan, no one can. She flashes an haughty smile and decides it's time for her to head on over to the Other Side. She grabs hold of Bonnie's shoulders but nothing happens. 'Are you broken?' she demands via her furious expression. Bonnie doesn't know what's going on either and why this particular journey has malfunctioned. Suddenly, a gust of wind extinguishes the candles in the church and the doors burst open. Howling air whips around the sacred site and some powerful, unseen force blasts Katherine backwards. She claws desperately at the ground but it is to no avail.

In While You Were Sleeping, while Elena was reading her diary, she saw an entrance Katherine wrote. She made a brief appearance in Elena's mind as a reconstruction of the motel scene with Stefan.

Season 8

In It's Been a Hell of a Ride, Kai revealed that when Cade the Devil died Katherine became the new ruler of hell.

In We're Planning a June Wedding, Katherine's remains were seen and a dagger made from her bones was created with the purpose to kill her. She also sent Kelly and Vicki Donovan to destroy Mystic Falls.

In I Was Feeling Epic, Katherine appears when Damon and Stefan were looking at Elena's empty coffin. She pretended to be Elena but when Damon hugged her he realized that she was Katherine. They asked about what she did to Elena and she said that she was hidden and that she would burn when Vicki used the Maxwell Bell to destroy Mystic Falls. Stefan stabbed her and she died. Katherine returned from the dead and was behind Damon when Stefan called him to inform him about Elena being trapped in Mystic Falls High School. Katherine told Damon that the bone dagger could kill and sent her to hell but it couldn't keep her there and that it was Kai Parkerwho casted the spell that trapped Elena. Damon asked what she wanted to release Elena and she said that she had everything she wanted. Damon stabbed her with the bone dagger and killed her. After having a plan to destroy hell, Damon went to the vampire tumb where Katherine appeared to irritate Damon. Damon told his plan to destroy her and at first she didn't believed it was possible, but then she thought he was just bluffing. Stefan appeared and she tried to leave, Damon stabbed her and she died again. Shortly after the Maxwell Bell unleashed hellfire, Katherine returned when Bonnie was redirecting the fire to The Armory. Damon grabbed Katherine and took her to the tunnel where the fire would kill them both. Stefan injected Damon with the cure allowing Katherine to escape but Stefan grabbed her and both died. Hellfire was sent back to hell where Katherine was, it destroyed hell and possibly her.