Lisa Trevor was imprisoned for nearly 30 years in the mansion and subjected to continual experiments that transfigured her into a monster. Numerous viral experiments made her immune to death itself and soon led Birkin to the discovery of the G-virus. Lisa has the disturbing habit of peeling faces from her victims and placing them over her own.
There were repeated attempts to dispose of her, but they all failed. She was eventually bound and left to wander the halls of the mansion.