Christine (Fallout: New Vegas)

Christine Royce is a knight of the Brotherhood of Steel, trapped in the Sierra Madre

Background
Formerly a scribe, Royce is a member of the Circle, a small contingent of the Brotherhood of Steel. When Elijah abandoned the Brotherhood after the defense of HELIOS One from the New California Republic Army, Christine was dispatched to track him down. She managed to locate him at Big MT. However, once she confronted her mark at Little Yangtze, they were interrupted by security robots. The elder escaped using the ghoulified Chinese prisoners as walking bombs while Royce was wounded and taken to the Y-17 medical facility for processing. During the course of experiments at the facility, her brain was damaged.

It was there that she was rescued by Ulysses, who blew up part of the facility just to get her out. She recovered with him for several days in a nearby cave, where they discussed philosophy and the failure of modern civilizations like the New California Republic or Caesar's Legion to forge a new future. Once Ulysses met the Think Tank and received his answers, the two separated. Christine left Big Mountain with the Mark I stealth suit and resumed her quest to find Elijah. Her original armor and rifle were left behind.

She eventually tracked him to the Sierra Madre Casino & Resort, where she was captured by his slave, Dog, and forced to work for him in breaking into the Sierra Madre while fitted with an explosive collar. At some point, she was also locked in an Auto-Doc in the Villa's Medical District by Dean Domino, where her vocal cords were torn out. The Auto-Doc repeated the procedure for two weeks in which Christine eventually developed claustrophobia as a result. She later regains use of her voice when the operation is completed by the Auto-Doc in Vera Keyes' hotel room. It is there that it is revealed that her capture and replacement of her voice was part of Domino's plan to break into the Sierra Madre vault, as the elevator could only be activated by the voice of the long-dead Keyes.

Quests

 * Find Collar 12: Christine: The Courier has to travel to the villa clinic to find her. Once inside, they have to release her and take her to the fountain in front of the Sierra Madre.
 * Mixed Signals: The Courier has to escort Christine to the Puesta del Sol switching station to get her ready for her part of the Trigger the Gala Event quest.
 * Last Luxuries: The Courier has to find and confront Christine in the Sierra Madre Casino & Resort.
 * Heist of the Centuries: Christine can use her new voice to unlock the elevator to the Sierra Madre vault. Additionally, she will turn off the turrets for the player during the fight with Elijah if she was kept on good terms.

Other interactions

 * When the Courier travels with Christine, she will be able to block out radio and speaker signals for a short time. She will also increase the amount of time taken for the collar to detonate.
 * She knows how to counterfeit Sierra Madre chips, and can give the player character the Coin Operator perk with the right dialogue options.
 * If the player character has at least 75 Medicine and initiates "You were badly hurt by that Autodoc" dialogue option, there is an additional dialogue option when discussing Christine's love interest ("Oh, girlfriend") and one can easily calm her down, stating that the player character understands her situation; if the player character has the Cherchez La Femme or Confirmed Bachelor perk there is an additional interaction with Christine when they leave her at her post before the Gala Opening. If the Courier accepts to hold Christine's hand, they can promise that they will return for her.
 * She can be intimidated with the Terrifying Presence perk to be forced into the elevator in the Mixed Signals quest. This results in a loss of Karma.

Appearances
Christine Royce appears only in the Fallout: New Vegas add-on Dead Money. However, her voice is also heard in the add-on Old World Blues and she is mentioned in the add-on Lonesome Road.

Bugs
If the player character has Dean Domino or Dog/God as a companion, the camera may center directly through the player character's head (or chest) during the first bit of dialogue with Christine.
 * A possible fix is setting any companions to wait before starting a dialogue with her.