- This article is for the prime universe version. For his alternate reality counterpart, see Lionel Luthor (Earth-2).
|“||If you're gonna take me on, son, you're gonna have to bring your game up to a whole different level.||„|
|~ Lionel Luthor, to Lex Luthor, "Tempest"|
Lionel Luthor is the secondary antagonist of the television series Smallville. Initially appearing in Season 1 as a recurring character, he served as the show's main antagonist in Seasons 2-3 before becoming a supporting villain in Season 4 and later an ally to Clark Kent in Seasons 5-7.
He was portrayed by John Glover, who also provided the voice of Edward Nygma/The Riddler in Batman: The Animated Series and played Dr. Jason Woodrue in the 1997 film Batman & Robin and Mr. Sivana in Shazam!
Lionel was born in Metropolis, the son of Scottish immigrants Lachlan and Eliza Luthor. He lived with his parents in a tenement in the city's Suicide Slum neighborhood. He was abused by his father while his mother was an alcoholic. He became close friends with Morgan Edge, with whom he later conspired to kill his parents so he could inherit their insurance premium and use it to start LuthorCorp, eventually becoming a rich and powerful business magnate.
Lionel married a woman named Lillian, with whom he had two sons, Alexander "Lex" Luthor and Julian Luthor (who was killed by his own mother soon after his birth). Despite being married, he had affairs with other women, resulting in the births of at least two illegitimate children: Lucas Luthor (born of an affair with Rachel Dunleavy, Lillian's nurse) and Tess Mercer (the product of an affair with Pamela Jenkins, Lex's nanny).
In the pilot episode, which opens in October 1989, Lionel is first seen riding a helicopter to Smallville, Kansas, bringing his 9-year-old son Lex along with him. He orders a scared Lex to open his eyes and look out the window, telling him that Luthors aren't afraid of anything and insisting that Lex has a destiny and he won't get anywhere with his eyes closed. Later, Lionel buys the Ross family's creamed corn factory. Not long after, a destructive meteor shower strikes Smallville, and Lex is caught in the onslaught. In the aftermath, Lionel frantically searches for his son in a cornfield and finds Lex rendered bald by the meteors and in shock. In the present day, Lionel sends Lex to run Smallville's LuthorCorp plant.
In "Hothead," Lionel confronts Lex over his decision to increase his workforce and challenges his son to a fencing match to resolve the matter; he bests Lex and demands that he cut 20% of his workforce by noon the next day. When Lex manages to find a way to save money without firing a single employee, Lionel grudgingly concedes the point, prompting Lex to suggest he's upset either because the plan works or because Lionel didn't come up with the plan himself.
In "Jitters," Lionel comes to Smallville in response to Earl Jenkins, a former LuthorCorp employee, taking hostages inside the town's LuthorCorp plant and demanding to be taken to a mysterious Level 3. He angrily confronts Lex over his handling of the situation, only to be interrupted by Jonathan Kent, with whom he is clearly acquainted. He then tries to negotiate with Earl, insisting there's no such thing as Level 3, causing Earl to angrily end communication with those outside the plant. When Lex decides to exchange himself for the hostages, Lionel opposes his decision but lets his son go into the plant anyway, impressed with Lex's show of bravery. When the hostages evacuate the plant save for Lex, Clark Kent, and Earl, he agrees to have the plant sealed to prevent gas from leaking out. Once the crisis is finally resolved and he's confronted by Lex over the existence of Level 3, Lionel stands firm by his claim that he moved on from Level 3 and lies to news reporters about what exactly Level 3 is, saying it's a redundant storage area.
In "Shimmer," Lionel drops by the Luthor Mansion to confront Lex about his relationship with Victoria Hardwick, the daughter of Sir Harry Hardwick, the CEO of LuthorCorp's business rival Hardwick Enterprises. He tells Lex that he sent him to Smallville as a test which Lex, at that moment, is failing, and claims that Victoria was sent by her father to distract Lex so Sir Harry can try to acquire LuthorCorp. The two have a tense argument that ends with Lionel telling Lex that, if he betrays his family, he'll always be alone in the world.
In "Leech," after Lex manages to trick the Hardwicks into leaving their company vulnerable for takeover by LuthorCorp, Lionel calls Lex to tell Lex he's proud of him, to which Lex dryly replies that means a lot coming from him. Lex then receives evidence from Roger Nixon that Lionel had been sleeping with Victoria, suggesting it was he who had sent her to tempt Lex as part of his "test."
In "Stray," Lionel comes to Smallville to congratulate Lex on his management of the LuthorCorp plant and to offer his son an opportunity to work alongside him as his Special Adviser. By the end of the episode, Lex turns down his father's offer on the belief that Lionel just wants to keep an eye on him because he views Lex as a potential rival. Lionel tells his son he's making a big mistake by turning him down.
In "Reaper," Lionel sends his right-hand man Dominic Santori to investigate Lex's finances, a move Lex assumes is payback for turning down his offer to come back to Metropolis. Later, Lex confides to Dominic that Lionel sees him as competition. In the final act, Lex meets with his father in a Metropolis alley, and the two exchange tense words before Lex tells his father to pop the trunk of his car. Lionel does so, and finds a bound Dominic. Lex then warns Lionel not to send one of his "drones" to investigate his finances. As Lex starts to leave, Lionel tells him "Well done."
In "Crush," it's revealed that Lionel threatened to disinherit Lex if his nanny Pamela Jenkins stayed, forcing Pamela to leave Lex despite her promise she'd never leave him following the death of his mother. Lionel later stops by the Luthor Mansion to talk with Lex about Pamela and reveals that Pamela is dying of cancer.
In the season finale "Tempest," Lionel visits the Smallville plant ostensibly to give the staff a congratulatory speech, only to then announce that the plant will be closing, pinning the blame on Lex's management. Lex immediately realizes his father is trying to force him to come back to Metropolis and determines to oppose his father's efforts. When Lex organizes an employee buyout of the plant, Lionel comes by the mansion to mockingly inform his son that he bought the Smallville Savings and Loan, meaning he now owns Lex's employees' bank accounts and can foreclose on any of them when they start missing payments, much to Lex's frustration. Lionel then challenges Lex, saying if he wants to take him on, he's going to have to bring his game up to a whole new level.
Later, as a violent tornado hits Smallville, Lionel again confronts Lex at the mansion, having figured out that Lex is using his late mother's LuthorCorp stock to fund his buyout. The two then argue angrily, and right after Lex declares war against his father and Lionel threatens to bury Lex and everyone who takes his side, the storm blows in a window and Lionel ends up trapped under a falling column. Lionel begs Lex to help him, and an injured Lex stares down at his father, seemingly contemplating letting his father die.
In the season premiere "Vortex," Lex rescues Lionel, who is hospitalized with severe injuries. Lex gives the go-ahead for the surgeons to operate on Lionel, but the procedure leaves Lionel blind.
In "Duplicity," Lionel comes to Smallville, wanting a reprieve from the physical therapists in Metropolis. Later, he is met by Dr. Steven Hamilton, who tells Lionel about the meteor rocks and the octagonal disk (the key to Clark's spaceship), piquing Lionel's interest. By the end of the episode, Lionel decides to stay in Smallville and dismisses Lex's suspicions that he really wants to follow up Dr. Hamilton's claims of extraterrestrial life in the town, saying he just wants to spend time with his son.
In "Red," Lionel makes alterations to the Luthor Mansion. When Lex confronts him for not asking his permission beforehand, Lionel guilt-trips his son into letting him go on with the changes. Later, he has his first meeting with Clark who, under the influence of Red Kryptonite, bluntly tells Lionel he's not welcome at the mansion and mockingly suggests he move in with the Kents (since Clark plans to leave Smallville). Moments later, when U.S. Marshal Ted Palmer enters the room and Clark takes his gun and fires it into his own palm, Lionel worriedly wonders what's going on, but Clark tells him not to worry and that Palmer missed. Sometime later, Lionel is told off by Lex for using his blindness as an excuse to wallow in self-pity, and he commends his son's directness, remarking he must have gotten it from Clark, all the while fingering the flattened bullets from Palmer's gun.
In "Nocturne," Lionel fires Tad, his latest assistant, for a mistake he made, and he gets into a bitter argument with Lex, whom he accuses of not doing enough to find him a suitable assistant. He leaves the study and goes outside, where he ends up throwing his electronic reader to the ground in a fit of frustration just as Martha Kent arrives. Martha reads the newspaper to Lionel who, impressed with Martha's business savvy, hires her as his personal assistant. When Lex angrily confronts him about hiring Martha, Lionel mocks his son for wanting to be a part of the Kent family, comparing him to the Greek god Prometheus who wanted to make a life among mortals. Lex angrily threatens to end their "father/son détente" if it turns out Lionel has an agenda that could be harmful to the Kents. Later, Lionel is confronted by Byron Moore, but is saved by Clark.
In "Lineage," Rachel Dunleavy shows up in Smallville, claiming that Clark is her biological son with Lionel. After learning that Lionel founded the agency that handled his adoption years ago, Clark confronts his parents, who then tell him about what happened after the meteors hit Smallville thirteen years earlier: After they found Clark, the Kents ran into Lionel, and Jonathan helped get an injured Lex to the hospital. Grateful to Jonathan for helping his son, Lionel told Jonathan to call him if there was anything he needed.
When he and Martha decided to adopt Clark, Jonathan called Lionel, who drew up paperwork to make the adoption look legitimate. Lionel, however, asked for something in return: He wanted Jonathan to convince the Ross family to sell their factory after they were having second thoughts about doing so. When Jonathan demurred, Lionel advised Jonathan to be careful with the adoption papers lest it come out that Clark's adoption was a sham; this prompted Jonathan to convince the Ross family to sell their factory, allowing LuthorCorp to gain a foothold in Smallville. The incident also sparked Jonathan's long-standing hatred and distrust of the Luthor family.
"Lineage" also reveals that Lionel indeed had an affair with Rachel, resulting in the birth of a son, Lucas. When Rachel takes Lex prisoner and threatens to kill him unless Lionel acknowledges Clark (whom she believes to be Lucas) is their son, Lionel refuses to yield to Rachel's demands. Fortunately, Lex is saved by Clark and Rachel is institutionalized. When confronted by Lex at the end of the episode, Lionel claims that Lucas died in infancy, but in actuality, the boy is still alive, as evidenced by a picture Lionel kept of a young Lucas.
In "Skinwalker," Lionel contends with protests against the building of a LuthorCorp office park on land belonging to the Kawatche tribe. When Lex attains ownership of the land (which includes the Kawatche Caves) through his own company LexCorp, Lionel suspects that his son knows that there's something valuable in the caves and determines to find out what.
In "Visage," it is revealed that Lionel tried to bribe Lex's girlfriend Dr. Helen Bryce to leave him; when she refused, he had the money wired to her account anyway, driving a temporary wedge between the couple.
In "Insurgence," Lionel is revealed to have had Lex's mansion office bugged with surveillance hardware, thus explaining how LuthorCorp was able to beat LexCorp at gaining a profitable business contract. Lex calls Lionel over to the Luthor Mansion to confront him on the matter, but Lionel contemptuously dismisses his son and leaves. Later, Lionel and Martha are taken hostage by a team hired by Lex to bug Lionel's own office, and it is revealed that Lionel's safe contains several bars of Green Kryptonite, a file on Clark, and the octagonal key to Clark's spaceship. Once he and Martha are rescued, Lionel tells Lex he's going to move out the mansion.
In "Suspect," Lionel is shot three times by an unknown assailant, and suspicion falls on Jonathan, who is found with the gun used in the crime. He is hospitalized and left in critical condition. According to a police statement given by Lana Lang, Lionel was confronted earlier by an angry Jonathan, who found an expensive watch that Lionel had given to Martha, ostensibly as a token of appreciation. Jonathan ordered Lionel to stay away from Martha, promising he would regret it. According to Lionel's employee Dominic Sanatori, Lionel and Lex earlier had a heated exchange over LuthorCorp buying out LexCorp, giving Lex a clear motive for shooting his father. Lex, however, later claims to Clark that Dominic was angry at Lionel for going back on an arrangement between the two of them.
It's ultimately revealed that Ethan Miller, Smallville's sheriff, is the shooter; earlier, Lionel blackmailed Ethan into his service and Ethan sought to get free of him. Lionel recovers and refuses to accept any responsibility for everything that's happened, instead laying the blame at Lex's feet. He tells Lex he forgives him for rebelling against him and tries to convince Lex to come back to work for him at LuthorCorp, but Lex just leaves the hospital room.
In "Prodigal," Lionel is reunited with his long-lost son Lucas, whom Lex found in Edge City and brought to Smallville in a plan to oust Lionel from LuthorCorp. Instead, Lucas sides with Lionel, and Lionel freezes Lex's bank account, disowns Lex, and kicks him out of the Luthor Mansion, forcing him to temporarily move in with the Kents. It is later revealed that Lionel has since regained his sight.
Lucas later takes Lex prisoner and calls Lionel, demanding he come to his LuthorCorp office. Lionel does, and reveals he's no longer blind to Lex, who is angered. Lucas then hands Lionel a gun and forces him to choose between killing Lex or killing Lucas. When Clark (who followed Lionel and is hiding in the air vent) hits Lucas's gun with a burst of heat vision, Lionel denounces his younger son as a "psychotic little bastard" and proceeds to shoot him many times, only to find that his gun is loaded with blanks. Lucas and Lex then reveal that they were working together all along to gain an advantage over their father.
By the episode's end, Lionel comes by the mansion as Lex moves back in, and he agrees to give Lex his company back. He then warns Lex that Lucas is a sociopath, but Lex leaves the room, sarcastically telling his father goodnight.
In "Witness," Lionel stops by the Luthor Mansion ostensibly to congratulate Lex on his pending marriage to Helen and to question his son about materials stolen from a LuthorCorp truck, which Lex denies any involvement with. After the Smallville Torch is vandalized, Lionel steps in and offers to repair it.
In "Accelerate," Lionel tries to give Lex an early wedding present, but Lex refuses. Later, he is spotted coming out of Peter Dinsmore's hospital room by Lex, who questions him about why he's spending so much time in Smallville. Lionel dodges his son's questions and warns him about his "paranoid delusions" before leaving. In the final act, Lionel is summoned to the mansion by Lex, who confronts him about him restarting the Level 3 experiments. Lionel denies any involvement and instead informs Lex that he managed to obtain conservator-ship of the Kawatche Caves from Lex, suggesting he informed the State Governor of a series of fatal accidents that occurred under Lex's supervision.
In "Calling," Lionel comes by the mansion to tell Lex that his injunction to keep him out of the Kawatche Caves has been rejected. Dr. Frederick Walden barges in and claims that Clark is an alien and must be killed for the good of all mankind before being sedated by a doctor. Lex later warns Clark that Lionel isn't going to let Walden's claims drop. Lionel later meets with Chloe to tell her that he's set up everything for her at the Daily Planet, but asks for something in return: a comprehensive profile on Clark. When Chloe rejects his offer, Lionel tells her that Clark is lucky to have a friend like her, and that he wonders if Clark has that same loyalty. By the end of the episode, Lionel examines Walden's charred remains and requests that the linguist's hand (which was remarkably left unharmed by the octagonal key Walden was holding at the time he was immolated) be sent to him.
In "Exodus," Lionel reveals to Clark his intentions to use a Kryptonite duplicate of the octagonal key (created using Walden's palm) to open the cave wall. Later, however, the Kryptonite key is stolen by Clark while Pete distracts Lionel and his employees down in the cave; Lionel is outraged by the theft. Later on, Lionel meets with Chloe, who accepts his previous offer to investigate Clark after she catches him kissing Lana following a promise they made to one another to be honest with each other. After Chloe leaves, Lionel is last seen holding an envelope he tried to give to Helen earlier.
In "Exile," Lionel meets with Chloe in the Kawatche Caves and asks for more information about Clark, but Chloe says she doesn't know anything more beyond what she's already given Lionel. Lionel later delivers an eulogy at Lex's funeral in Metropolis, but when Helen shows up alive and well, he angrily leaves. When Helen arrives at the mansion later on, Lionel confronts her and warns her that a predator is only another predator's prey.
In "Phoenix," Lionel is confronted by Lex, who has returned from a deserted island. Lex angrily accuses Lionel of engineering his plane crash, but Lionel denies any involvement and insists that Helen is responsible, prompting an enraged reaction from Lex. It's later revealed that Lionel is good friends with crime boss Morgan Edge, whom he demands returns a stolen sample of blood (from Clark). In the end, Lionel comforts Lex over falling for Helen (who's revealed to have arranged for Lex's death, thus proving Lionel was right) and reluctantly accepts Lex back into the LuthorCorp fold.
In "Extinction," Lionel welcomes Lex back to LuthorCorp and has him sign an insurance premium, which arouses Lex's suspicions. Later, he checks on Lex after an attempt on the latter's life by Van McNulty. In the final scene, Lionel confronts Chloe over her keeping notes on Lex and sternly warns her that there will be consequences if she investigates any other member of his family.
In "Slumber," Lionel insists that Lex undergo a full psychological evaluation so he can be assured that Lex is trustworthy.
In "Perry," it is stated that a reporter Perry White uncovered incriminating evidence on Lionel, who ruined his reputation.
In "Relic," Lionel reveals to Lex that he made up his family's privileged background as Scottish nobles to impress his Ivy League peers and to distance himself from his abusive parents, and that his parents died in a tenement fire years ago. Later, Lionel is informed by Lex that his parents were, in actuality, murdered.
In "Magnetic," Lionel is revealed to have been friends with Edge since childhood. The next episode, "Shattered," reveals that Lionel schemed with Edge to have his parents murdered so he could inherit their life insurance and use the money to found LuthorCorp. After Lex is attacked at the mansion and he flees to the Kent Farm for refuge, Lionel later shows up and questions Clark about Lex's whereabouts. Clark falsely claims he hasn't seen Lex in a few days, and Lionel tells him that Lex has had a psychotic break and needs to be committed.
Later in the episode, Lionel finds Clark at the hospital after Lana is trampled by a horse following a violent reaction from Lex who's now missing, and he mockingly compares the teenager to Sancho Panza from Don Quixote. When Clark starts to walk away in disgust, Lionel demands to know where he's going, and Clark replies he's going to look for Lex and warns Lionel to be careful because his son is convinced he's responsible for everything that's been happening to him. Lionel implicitly blames Clark for Lana's injury, and when Clark starts to protest, he cuts him off and angrily tells him if he had told him where Lex was earlier, Lex would have gotten the help he needs and Lana wouldn't have been hospitalized. When Chloe arrives, Lionel calms down and assures Clark his bodyguards are well-equipped to protect him before telling Clark and Chloe to go home before they cause any more damage. He then leaves.
Next, Lionel enters his office at LuthorCorp, where his bodyguard is knocked out by Lex, who takes the bodyguard's gun and holds his father at gunpoint, ranting crazily about how Lionel is conspiring with Edge to drug him and make the world think he's insane so Lionel can avoid jail time for his parents' murder. Lionel insists he had nothing to do with his parents' deaths. Lex then begins hallucinating hearing his baby brother Julian crying, and Lionel tries to convince Lex that Julian is dead and assure him that he knows Lex didn't mean to hurt his brother. In a rage, Lex demands that Lionel give him Edge's location; Lionel complies and cautions Lex to be careful because he can't bear to lose another son. Lex then knocks his father unconscious.
Lex confronts Edge at his hideout, and Edge confirms that he and Lionel did conspire together to drug Lex so people will think he's losing his mind. By the episode's end, Lionel meets with Dr. Claire Foster (who's also a part of the conspiracy to discredit Lex) at the Belle Reve Sanitarium, and the two of them observe an institutionalized Lex in his cell. Lionel tells Dr. Foster that he loves his son, but he has no choice but to drug him and keep him in Belle Reve in order to keep the truth about his parents' murder hidden.
In "Asylum," Lionel visits Lex, who's bound to his bed following an escape attempt, in Belle Reve, and expresses his sadness over seeing Lex in such a state. Lex tries to convince his father that he's cured, but when Lionel proves resistant and says he only wants to help his son, he replies that all Lionel is interested in staying out of jail. Lionel remarks that it's tragic when a mentally-ill man is convinced he is sane, prompting Lex to start ranting angrily at him. Lionel then leaves.
Lionel meets with Dr. Foster and demands that Lex be subjected to a radical electroshock treatment to erase his memories of the past several weeks. When Dr. Foster is later persuaded by Clark and Chloe to cancel the procedure, she's later reported to have been killed in a car accident, mostly likely arranged by Lionel. Later, Lionel is in the room where Lex is strapped to a table and about to be given electroshock treatment, and he tells a protesting Lex to be strong. Lionel then watches with barely-restrained sadness as Lex is subjected to the treatment. In the final act, Lionel is angered to find out that Lex knew Clark's secret prior to his memories being erased.
In "Whisper," Clark's newly-activated super-hearing causes him to overhear a private phone conversation between Lionel and Chloe, during which Lionel voices his intentions to have Lex sit in his office and "sharpen pencils" due to his mental illness. Later, after a conversation with Lex about his remark to Chloe, Lionel assumes Chloe was the one who relayed his words to Lionel and calls Chloe to his office at LuthorCorp, where he informs her that her Daily Planet column has been cancelled, despite Chloe's insistence that she didn't tell Lex what Lionel said to her.
In "Obsession," Lionel greets an Advanced Economics class (which includes Clark and Chloe) who are on a field trip to LuthorCorp, and gives a speech about business before handing the class back to their teacher. In the final scene of the episode, Lionel meets with a restrained and deteriorating Adam Knight, who is revealed to have been sent by Lionel to spy on Lana and Clark, and he chastises him for failing his mission. When Dr. Lia Teng enters with Adam's medication (a serum that brings people back to life), Lionel coldly announces that Adam is no longer part of LuthorCorp's research program, ignoring Dr. Teng's protests that Adam will die without the serum and even holding said serum just inches away from Adam's face before leaving the room as Adam cries for help.
In "Resurrection," Clark tells his parents that Lionel has figured out a way to use his Kryptonian blood to make a serum that brings people back to life.
In "Crisis," Lionel is confronted by Lex about the Lazarus Serum, but he denies any involvement, only to be surprised when Lex asks to be put in charge of the project. Next, Lionel has his men enter Metron Labs and take away vials of the serum, and he orders Dr. Teng to have the lab cleared out by the end of the day lest he have her deported to North Korea before leaving Metron. Later, after Lex and Clark find Dr. Teng and her technicians murdered and Lex confronts him about what happened, Lionel refuses to accept any responsibility and remarks to his son that he isn't worried because he knows he has someone to handle things, making it clear that he's going to pin the blame on Lex, who refuses to help his father and storms out of the office.
In the episode's final act, Lionel talks with Dr. Burgeon about the Lazarus Serum and insists that the doctor have a lab set up by the end of the week. When Dr. Burgeon tells him that things take time, Lionel replies that time is a luxury he can't afford because he's terminally ill with a disease affecting his liver. The episode ends with Lionel, disheveled and depressed, alone in his office. After shutting the window blinds, he sits down on his couch, takes out a gun, and aims it at himself.
"Legacy" picks up where we left Lionel. Before he can pull the trigger, he receives a phone call informing him that Clark is in the Kawatche Caves. Lionel heads to the caves and finds Clark there; after a brief conversation, Lionel notices that the octagonal keyhole is back on the cave wall and suspects that Clark is responsible for its re-appearance. He tries to get Lex to work with him on uncovering Clark's secret, unaware that his conversation with his son is being recorded by the FBI.
Later, Lionel travels to New York and meets with Dr. Virgil Swann, from whom he attempts to extract information about Clark, only for Dr. Swann to outmaneuver his efforts and correctly deduce that Lionel is dying. The two then form a mysterious arrangement. Next, Lionel has a team conduct tests on the Kawatche Caves, determined to unlock the secrets within despite Clark's insistence he'll never find what he's looking for. Lionel also hires a team to pose as FBI agents and illegally search the Kent Farm for the octagonal key to no avail (since Jonathan kept hold of the key).
In the final act of the episode, Lionel is confronted in the caves by Jonathan, who orders the technicians and Lionel's goons to leave. Lionel and Jonathan exchange words about the caves, and Lionel's snide remark to Jonathan about how Clark learned his weaknesses from him prompts a violent confrontation between the two men. As Lionel is pushing Jonathan against a wall and attempting to gouge out his eyes, the key activates and glows brightly in Jonathan's pocket. Lionel reaches in and takes out the key, which hits the ground. He moves toward the key, only to be restrained by Jonathan. The two of them watch as the key floats into the air and makes contact with a glass pane. Lionel is nearly killed by Jonathan, who is stopped by Clark. Once things settle down, Lionel sees the keyhole is sealed over once again and suspects the key is inside the wall (in actuality, Dr. Swann has somehow obtained the key).
In "Truth," Lionel calls Lex to his office to ask about an accident that occurred at the LuthorCorp plant and questions his son about whether a biological agent had been released. When Lex is evasive about the issue, Lionel claims he's only concerned about him and wonders if Lex is keeping secrets from him, to which Lex replies they all keep secrets before leaving. Later, Lionel visits Chloe in the Smallville Medical Center, and Chloe uses her newfound ability to make anyone tell the truth to get Lionel to admit he had her father blacklisted and that he also plotted with Morgan Edge to kill his parents for their insurance money. Chloe records Lionel's confession on her phone and tries to blackmail Lionel into helping her father, but Lionel stops her from leaving the room and convinces her to go to the Kents and get them to reveal the truth about Clark.
Sometime after that, Lionel again calls Lex to his office, and tells him that, in the future, if he wants to restart one of his old projects, all he needs to do is ask. Lex pointedly replies he wouldn't have to resort to subterfuge if Lionel had kept him informed. Lionel wonders why Lex would be so desperate to uncover the truth that he would be willing to use an unstable drug; when Lex then replies that the truth has never held much merit to him, Lionel, in a fit of exasperation, demands that Lex tell him what he wants from him, but Lex simply replies it doesn't matter because he's never going to get it (earlier, Lex admitted to Chloe that the reason he doesn't just walk away from his father is because he wants Lionel to love him). At the end of the episode, Lionel leaves a phone message for Chloe, informing her that he had his confession erased from her phone.
In "Memoria," Lionel is visited by Clark, who tries to persuade him to shut down the Summerholt Neurological Institute to prevent Lex from recovering his memories of Lionel's involvement in his parents' murder. Lionel turns the tables and discerns that it's Clark who doesn't want Lex to regain his memories, showing the teenager footage of a conversation between Clark and Lex (before Lex's electroshock treatment) in which Lex tells Clark he knows his secret. Lionel then visits Lex at the mansion and tries to convince Lex to stop the treatment, only for Lex to experience past memories, one of which shows Lionel discovering Lex standing over Julian's crib after apparently killing Julian by accident and then striking Lex in a grief-filled rage. When Lex collapses but recovers, Lionel tells Lex he's playing with fire, only for Lex to accuse him of not wanting him to regain his memories. Lex then orders his father to leave.
Lionel comes by the Kent Farm to talk with Clark, and he tells him that their meddling has prompted Lex to accelerate the process of reclaiming his memories. However, it turns out to be a trap set by Lionel, and Clark ends up being taken captive by Dr. Lawrence Garner and his technicians when he arrives at Summerholt to find Lex. As it happens, Lionel made a deal with Garner to stop Lex's treatments in exchange for Clark being exposed to the same treatment so Lionel can learn the truth about Clark's origins. Unfortunately for Lionel, Lex calls him out of the meeting, claiming he's regained his memories, and Lionel leaves the lab, telling Garner to wait for him. Garner goes ahead with the procedure but ends up causing an explosion.
By the episode's end, Lionel enters his office at LuthorCorp to find Lex waiting for him. Lex reveals to Lionel that he didn't kill Julian; it was Lillian. A disbelieving Lionel warns Lex not to desecrate his mother's memory, but Lex tells him he blames his father. Lex then reasons that Lillian murdered Julian because she wanted to spare Julian from Lionel's abusive parenting. Lionel, shocked and angry, starts to leave, but turns back and questions Lex why he took the blame for Julian's death, to which Lex replies that, because he was Lionel's sole remaining heir, Lionel wouldn't do anything to him, whereas Lillian wouldn't have been spared Lionel's wrath. Lionel is then hit with the awful realization that he hated Lex all these years for nothing, and he tries to apologize to his son, only for Lex to refuse and leave.
In "Talisman," Lionel meets with Professor Joseph Willowbrook and his teaching assistant, Jeremiah Holdsclaw, about a newly-unearthed Kawatche artifact that Jeremiah recognizes as "Palak." Lionel refuses to allow the two Kawatche to take the artifact for study, causing Jeremiah to grab the artifact and smash it with a rock, revealing the Starblade which imbues Jeremiah with superhuman powers. Jeremiah sends Lionel flying, injuring him. After Jeremiah flees, Lionel orders for the Starblade to be retrieved.
At the Smallville Medical Center, Lionel is being treated for bruised ribs when Lex arrives. Relations between Lionel and his son remain tense after the previous episode, and Lionel tells Lex he doesn't want his help. Lionel later visits Willowbrook at Central Kansas A&M and talks with him about the Starblade, which can also reveal the identity of Sageeth, the bearer of darkness in Kawatche legend and archnemesis of Naman, the Kawatche's savior. When Clark arrives to speak with Willowbrook, Lionel greets the younger man cordially and departs.
Later on, Clark finds Lionel waiting for him in the Kents' barn, and Lionel tries to convince Clark to speak to the Kawatche on his behalf, explaining to Clark that he believes the Starblade to be made of the same alien metal as the octagonal key and thus hopes to use the Starblade to create another duplicate of the key so he can open the cave wall. Lionel threatens to become the Kawatche's enemy, prompting Clark to order him to leave his family's property; Lionel does.
Lionel is riding in his limo when the limo stops, and he asks his driver what's going on, only to be met with silence. He then turns to see Jeremiah standing outside his door. Jeremiah takes Lionel captive and binds him to an altar on an ancient Kawatche ritual ground, intending to sacrifice Lionel, whom he believes is Sageeth. Clark arrives to stop Jeremiah, and the two battle in the surrounding woods. Moments later, Lex arrives and frees his father. When the Starblade lands on the altar, Lionel and Lex both grab at the Kawatche weapon, causing it to turn to dust, leaving it uncertain who will become Clark's greatest enemy.
In "Forsaken," Lionel meets with Peter Dinsmore about the clone of Emily, who's grown into a teenager and developed the ability to phase through matter. He insists to Dinsmore that Emily is a dangerous liability to LuthorCorp and decides to send Dinsmore to retrieve Emily. Later, Lionel calls Lex to his office at LuthorCorp and reveals he knows Lex has been working with the FBI to investigate him for murder. After angrily dismissing Lex, he receives a call from Agent Loder and orders him to interrogate Pete in order to find out the truth about Clark.
At the end of the episode, Lionel is sitting in his office, listening to music, when Lex enters. Lionel assumes Lex has come to ask forgiveness, but Lex coldly tells his father he hasn't. The two exchange words before Loder enters the office and places Lionel under arrest for the murder of his parents. Before being taken out of the office in handcuffs, Lionel warns Lex that "Judas hung himself with his own rope."
In "Covenant," Lionel is put in jail to await trial, and he insists to Loder that he continue his investigation of Clark, only to be refused. When Lex comes by to visit him, Lionel reveals his terminal illness, only to be met with a cold response from his son. Lionel later has a key mailed to Clark, who confronts him. The key, as it turns out, opens a door to a room where Lex has kept keepsakes and notes about his obsession with Clark; this revelation prompts Clark to end his friendship with Lex. Lionel is tried for murder and escorted back to jail. By the episode's end, Lionel has his hair shaved.
In "Crusade," Lionel, still imprisoned, is visited by Lex, who questions him as to the whereabouts of an ancient relic that was stolen from Lex (by Kal-El, Clark's Kryptonian personality) while he was flying aboard his jet. Lionel denies any knowledge and vows that the people responsible for putting him in prison will feel his wrath, at which point Lex mentions Chloe. Lionel then denies any involvement in Chloe's supposed murder. Later, he is visited by Lois Lane, Chloe's cousin, who suggests that he's being set up.
In "Gone," he sends a metahuman named Trent MacGowen to find and kill Chloe so she can't testify against him. The effort fails, and Lionel is sentenced to prison.
In "Scare," Lionel is released from prison, despite his insistence that he feels he has to remain in jail and be an example to others. Later, Lionel leaves prison and meets with the person responsible for his release, whom he greets happily before climbing into the unknown person's limousine.
In "Unsafe," Lionel comes by the Luthor Mansion, and Lex agrees to let him stay in the guesthouse.
In "Sacred," Lionel allows Clark and Lana to use the LuthorCorp jet to travel to China and find one of the Stones of Power. Later, he cautions Lex about his search for the Stones of Power.
In "Ageless," Lionel meets with Genevieve Teague, who orders him to hand over one of the Stones of Power or Lex will be killed. Lionel tries to warn Lex about Genevieve, but Lex insists he always watches his back. Later on, Lionel meets with Genevieve again, and the two share a bottle of wine. He then gives a speech about parenthood as Genevieve begins choking, revealing that Lionel spiked the wine. Lionel takes out the antidote and makes it clear to Genevieve that he will not tolerate any threat against his son, then demands that she hand over the artifact.
In "Commencement," Lionel has Lana's apartment cleaned up following Isobel's murder of Genevieve using the Crystal of Air, and then demands that Lex give him the Crystal of Water in exchange for Lana's safety. Later, he confronts Lex at the Luthor Mansion and insists to Lex that he doesn't have the stone. Once Clark unites the Crystal of Air with the Crystal of Fire, the Crystal of Water is revealed to have been in Lionel's possession all along; it activates and Lionel is exposed to its energy, going into a seizure before laying still on the floor. Before having his father taken to another room, Lex informs his father's silent body that Lionel did create the son he always wanted. Lionel is last seen in a catatonic state, with Kryptonian symbols seen deep in his eyes.
In "Arrival," Lana discovers Lionel in a strange trance with his eyes glazed over, scratching a Kryptonian symbol on the floor of Lex's office. Lionel then looks at the Kryptonite in Lex's safe and says "Their home is their poison," leading Lana to realize that the green meteor rock is Nam-Ek and Aethyr's weakness.
In "Mortal," Lex has Lionel committed to Belle Reve. In the following episode, "Hidden," Lex confronts his father about the Kryptonian symbol that appeared on the underbelly of the black ship that crash-landed during the second meteor shower. Lionel, still in his trance, only says "Only he can open it." Later, when Clark is shot and dies, Lionel, suddenly displaying superhuman strength and speed, breaks out of Belle Reve. When Clark wakes up in the Fortress of Solitude, he is greeted by Lionel, who addresses him as "Kal-El." Clark demands to know how he knows that name and "Lionel" replies he's his son, causing Clark to realize Lionel is actually Jor-El. Jor-El explains that when the Crystal of Water was activated after Clark united the other two Stones of Power, Lionel's body became a vessel for him to inhabit should Clark need his help. Later on, Lionel reappears at the Luthor Mansion, back to normal but claiming to have no memory of what happened the past few weeks.
In "Reckoning," after Jonathan wins the Kansas Senate election, Lionel calls to congratulate Jonathan and asks to meet with him in the Kent barn. Jonathan drives home and confronts Lionel, saying he's going to pay him back for his campaign contributions. Lionel then shows Jonathan a photo that enrages Jonathan, who punches Lionel and roughs him up a bit before ordering him to get off his property and dying of a heart attack moments later. Lionel is later present at Jonathan's funeral in the final act.
In "Vengeance," Lionel comes by the Kent Farm to give Martha his condolences for Jonathan's passing. Later, he tries to re-take control of LuthorCorp from Lex, since Lex's campaign for the Kansas Senate seat left the company vulnerable. Lex, however, finds evidence that Lionel met with Jonathan right before his death and forces Lionel to hand control of LuthorCorp back to him. Lionel is later confronted by Andrea Rojas, whose mother was murdered by thugs hired by Lionel. Fortunately, Lionel is saved by Clark, whom he thanks.
In "Cyborg," Lionel helps Martha against a blackmailer who, as it turns out, was hired by Lionel himself. The episode ends with Lionel playing a DVD containing footage of Clark using his powers to save Lana from an explosion and saying to himself, "Your secret is safe with me...Kal-El," revealing he knows the truth about Clark.
In "Mercy," Lionel and Martha are taken captive by Lincoln Cole, a former LuthorCorp employee who forces them to play dangerous games. Fortunately, they are saved by Clark. Later, Clark confronts Lionel, who reveals he's known his secret ever since he was exposed to one of the Stones of Power. Lionel tries to assure Clark he doesn't want to hurt him or his mother, but Clark refuses to believe him and demands that Lionel stay away from Martha. After Clark leaves, Lionel suffers a seizure and collapses to the floor.
In "Oracle," Lionel confronts Lex over his partnership with Milton Fine, but Lex treats him dismissively. After Lex leaves, Lionel experiences another seizure and his eyes turn white, then he scribbles down a Kryptonian message on a piece of paper. Later, Lionel meets with Clark in the Kents' barn, and Clark angrily confronts him over suspicions that Lionel wants to use him as a weapon as well as Lionel's role in Jonathan's death. As Clark roughs him up, Lionel explains he was trying to gain Jonathan's allegiance but Jonathan took it the wrong way. A simulacrum of Jonathan then appears and urges Clark to kill Lionel, who insists to Clark that the real Jonathan wouldn't want him to become a murderer. Clark ultimately attacks "Jonathan," who reveals himself as a Brainiac duplicate. Lionel is then possessed by Jor-El, who dispatches the duplicate.
Lionel brings Clark to his office and shows him his vault, which is filled with papers covered with Kryptonian symbols which Lionel claims is a message for Clark from Jor-El; Chloe later translates the symbols as meaning "Zod is coming." Later on, Lionel comes to the Kent farmhouse and admits to Martha that he met with Jonathan right before he died, then leaves.
In "Vessel," Lionel offers for Martha and Lois to take the LuthorCorp jet to Washington, D.C. Later, he visits Clark in his loft and shows him a Kryptonian message he says he wrote in his sleep; Clark deciphers the message as "Sacrifice the vessel" and tells Lionel that Jor-El wants him to kill Zod's human vessel to prevent Zod's escape from the Phantom Zone. When Clark claims he can't take a life, Lionel tells him that the true test of a hero is knowing when the greater good will be served by an evil act, and is shocked when Clark reveals that Lex is the vessel for Zod. Lionel then finds Lex in the field he was abducted from earlier, only to find that Lex has somehow gained Kryptonian abilities. Later on, Lionel rescues Chloe as rioting breaks out in Metropolis following Brainiac unleashing a computer virus that shuts down technology all over the world. However, rioters break into Lionel's limo and drag him and Chloe out.
In "Fracture," Lionel's past abusive behavior towards Lex and Lillian is seen.
In "Descent," Lionel arrives at LuthorCorp and enters his office, sitting silently and at a loss over what to do, when Lex steps out the shadows and confronts him about Veritas and what he knows about the Traveler (Clark). Lionel keeps Clark's secret and tries to convince Lex to stop his pursuit of the safety deposit box in Zurich, warning him if he opens the box, there will be no redemption for him ever. Lex refuses to listen and sends Lionel falling out of the window to his death. By the episode's end, Clark finally recognizes Lionel has truly changed for the better and pays his respects to Lionel at his funeral, sprinkling dirt onto his grave.
In "Abandoned," it is revealed to that Lionel is Tess' biological father.
In the story arc "Detective", it was revealed that Lionel tried to recruit Thomas and Martha Wayne into the Veritas, it was unknown how Lionel reacted after they rejected his offer. However, Bruce Wayne is an old friend of Lex Luthor as a result of this.