Find Collar 12: Christine

 is a quest in the Fallout: New Vegas add-on Dead Money.

Quick walkthrough

 * Travel to Villa Clinic area.
 * Retrieve basement key from second floor. It is located in a desk in one of the rooms.
 * Travel to the basement to de-activate the shielding on the intercomms.
 * Do this by using the console in the basement and shutting off the power.
 * Travel back to the first floor. Interact with the malfunctioning chamber to release Christine.

Detailed walkthrough
WARNING: There is currently a bug that doesnt allow you to complete dead money or Level up Behtesda and Microsoft are releasing and update to correct the issue.