Helga Katrina Sinclair

"Commander, there were not supposed to be people down here. This changes everything."

- Helga discussing about the Atlantean natives.

Lieutenant Helga Katrina Sinclair (or better known as Helga Katrina Sinclair, Helga Sinclair, or simply Helga) is the secondary antagonist of Disney's 41st full-length animated feature film Atlantis: The Lost Empire. She is the right-hand of Commander Lyle Tiberius Rourke.

She was voiced by Claudia Christian, who also played Fairy Godmother in the Shrek 2 videogame.

Personality
While being clever and loyal, Helga is cunning and manipulative. She is a powerful and intellectual master at manipulating others to do her will, using her sharp tongue and good looks. She is also an energetic, aggressive and belligerent fighter who embraces her anger, sarcasm, and greed when she feels she has to get physical. Despite all of this, she appears to have a sympathetic and charming side, as she is suspicious and reluctant (even though she goes through with it) to attempt genocide, and will turn against those she feels have betrayed her.

Biography
Helga first appeared in the apartment of Milo James Thatch (the protagonist of the film), where she introduces herself to him and announced that her employer Preston Whitmore (who is a close friend of Milo's grandfather Thaddeus) is funding an expedition to find the lost city of Atlantis and that he wants Milo to be a part of. Sensing this as an opportunity to prove his claims about Atlantis true to the public, Milo happily accepts the proposition.

During the journey, Helga is seen aiding her boss and the team into successfully locating the lost city (thanks to Milo's deciphering of the Atlantean language on the Shepherd's Journal); she even took note to see how happy Milo is after finding the lost city. However, it turns out that Helga herself is aware of the existence of a powerful crystal called the Heart of Atlantis and that she, Rourke and their soldiers are planning to steal it to make themselves rich. Despite her greedy and treacherous nature, Helga becomes remorseful when she discovered they were going to steal from an ancient yet living civilization and showed some concern over it, though this did not stop her from going along with the plan.

During the final battle, Helga uses her pistol to shoot back against the heroes, but Milo crashes his flying stone fish into the blimp, causing it to descend further. To lighten the load on the balloon, Rourke betrays Helga by attempting to throw her off, but she glides back and beats him up, berating Rourke for his treachery. However, Rourke grabs her foot and successfully throws her out, where she hits the base of the volcano while Rourke taunts her by saying that it is nothing personal.

Using the last of her strength, Helga repeats the exact words that Rourke said to her as she manages to fire a flare gun at the blimp, causing it to descend rapidly further. This allows Milo to defeat Rourke by crystallizing and shredding him to pieces with the blimp's propellers and return the crystal to save Atlantis from an imminent volcanic explosion. It is unknown whether she died afterwards from her fall or if she was killed when the destructive volcano erupted. In fact, her fate is currently unknown.

In the end, the crew return back to the surface while Milo stays behind in Atlantis to help rebuild its former glory, and they (along with Mr. Whitmore) form a cover story to keep the existence of Atlantis as a secret, describing Helga's fate as that she went missing in action, though Cookie almost spilled the beans on Helga's true circumstances before Mrs. Packard silences him.

Quotes
"Milo James Thatch? (Milo: Wait, who are you? How did you get in here?) I came down the chimney. Ho... ho... ho. My name is Helga Sinclair. I'm acting on behalf of my employer who has a most entreating proposition for you. Are you interested?"

- Helga meeting Milo in his apartment.

"This way, please? And don't drip on the Carvaagio. Step lively, Mr. Whitmore does not like to be kept waiting. (Milo and Helga enter the elevator) You will address him and 'Mr. Whitmore' or 'Sir'. You will stand unless you asked to be seated. Keep your sentence short to the point, are we clear (Milo nods while gulping in fear) And relax, he doesn't bite.... often."

- Helga giving a tour in Mr. Whitmore's mansion.

"Diving officer, submerge the ship. Make the depth 1-5-0 feet."

- Helga ordering the submarine crew to lower their submarine into the water to start the expedition.

"Cartographer, linguist, plumber.... hard to believe he's still single."

- Helga commenting on Milo's presentation of the legend of the Leviathan.

"Load the torpedo bays! Subpod crews, battle stations!!"

- Helga ordering the subpod crew to arms after realizing that the Leviathan actually exists.

"Move it, people! Some time today would be NICE!!"

- Helga ordering the crew to get to the escape pods during the Leviathan's attack.

"Moliere, you're on point. No, Vinny! Audrey's taking the oiler. You know the rule: I want you 500 feet behind that truck at all times. And Packard, put out that cigarette."

- Helga starting up the expedition through the ancient remnants of Atlantis.

"Someone's having a good time."

- Helga commenting on how happy Milo is following the successful discovery of the lost city of Atlantis.

"C'mon, let's get this over with. I don't like this place."

- Helga after seeing the crystal chamber lighting up.

"That's it, unless someone wants to jump. (Rourke: Ladies first!) (tosses Helga off, but she swings from the railing and jumps back in and kicks Rourke in the face.) You said we were in this together! You promised me a percentage!! (Rourke: Next time, get it in writing!) (Rourke throws Helga off again) NOOOO!!!"

- Helga being betrayed after Rourke throws her overboard.

"Nothing... personal."

- Helga's last words as she fires a flare to blow up Rourke's blimp in revenge of his betrayal.

Trivia

 * Though she chose to accompany Rourke when he left with the Heart Of Atlantis, she had second thoughts about stealing from Atlantis when it became apparent that the Atlanteans were not extinct and that their city was still thriving.
 * This, along with Rourke's betrayal, has led to several fan theories that Helga changed her ways and joined the Atlanteans during the film's climax. Some even go so far as to suggest that she not only survived her fall from the balloon but was pardoned by and joined the Atlantean society. The Disney Wiki even states this in the article for the character, though there is no canonical evidence for this.