It's Christmas Eve and Angela Bridges, who is an ambitious young executive, is working late before she leaves for her family's holiday party. When she gets down to the parking garage, she discovers that her car won't start. The garage is deserted and her cell phone won't get a signal underground. When Thomas, a friendly security guard, comes along and offers his help, Angela nervously accepts his gesture of good will. When his attempt to start her car fails, Thomas invites her to stay and share a small Christmas dinner he's preparing in the parking office. Angela laughs it off, not realizing that this invitation is no laughing matter. Thomas has been watching her closely, for months. His dinner invitation is not optional and if Angela wants to live to see Christmas morning, she must find a way to escape parking garage level P2.