Christine (Fallout: New Vegas)

Christine Royce is a former scribe of the Brotherhood of Steel and a knight of The Circle, trapped in the Sierra Madre

Background
Christine was formerly a scribe with the Brotherhood of Steel. In her youth, she met another scribe, Veronica, and the two became romantically involved for a time. Veronica's mentor, Father Elijah, used his status to separate the two. This was unbeknownst to Veronica, who believed Christine left to distance herself from her staunch procreation parents. Following this, Christine found a new purpose under the same banner, becoming a Knight within the The Circle, a group of Brotherhood hardliners. After the Brotherhood's defeat at Helios One at the hands of the NCR, Elijah went rogue in search of "Old World" technology that could help him "wipe the slate clean", leaving a trail of crimes in his wake. Christine was ordered by the Circle to track him down and kill him.

Christine followed Elijah to the Big MT, tracking him to Little Yangtze experimenting on the survivors with bomb collars. Elijah used the survivors against Christine "like walking bombs" and was knocked unconscious. She was hauled by medical robots to the Y-17 medical facility. At Y-17, she was lobotomized, having her head cut open and jabbed with electrodes, causing impairment in her ability to read and write, along with deep facial scars. Another visitor at Big MT, Ulysses, arrived to rescue her, carrying her out to Ulysses' Point to nurse back to health. Ulysses visited the Think Tank for answers of his own and met Elijah there, learning that his next destination was the Sierra Madre. Christine would repair a holotape recorder for Ulysses, before parting ways.

At the Sierra Madre, Christine was fitted with a slave collar by Dog/God and eventually trapped by Dean Domino inside an Auto-Doc for two weeks, removing her vocal chords to replace with Vera Keyes' voice, as part of his Sierra Madre vault heist.

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.

Behind the scenes

 * Christine's name was recycled from the Van Buren character, Christina Royce. Christina was a returning character from Fallout 2, Chrissy. She would've been an NCR corporal and a recruitable companion.

Appearances
Christine Royce appears 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.