A couple attempts to recover from a devastating trauma by repairing a derelict house in a small town, only to discover a door in the basement that holds a sinister secret. In the wake of a nervous breakdown, Christine and her husband Barry purchase a neglected fixer-upper and invite Christine's sister Lisa to move in with them. Completely blind to the fact that her husband and sister are having an affair despite the fact that they practically flaunt it in front of her, Christine becomes obsessed with a mysterious room in the basement that's been sealed with a titanium door and an elaborate lock mechanism. Meanwhile, as Christine attempts to gain access to the tightly sealed room, her next door neighbors - an eccentric elderly couple - know exactly what dwells on the other side. A vampire has been locked in the basement for decades, and by allowing it to infect them, the sadistic senior citizens can achieve immortality. One day, while her husband is at work, Christine summons a locksmith to unlock the door, and satisfy her curiosity once and for all. Once the bloodsucker is unleashed, Christine and the locksmith attempt to coax him back in the room before the entire town is infected.