After opening in 1871, Danvers State Mental Hospital has been sitting dormant since 1985, but that's about to change as plans call for its renovation. Unfortunately, the place is full of asbestos and other dangerous materials that must be removed prior to that, so various companies have been bidding for the job. Among them is the Hazmat Elimination Company, and owner Gordon Fleming (PETER MULLAN)-who's recently had a baby and some marital and financial difficulties - is so desperate for the work that he promises he can finish the job in just one week.
That doesn't sit well with Phil (DAVID CARUSO), the crew chief, who realizes the enormity of the job and what little time that gives them to complete it, especially with Hank (JOSH LUCAS) working for them. Phil's never liked Hank since he stole away Phil's girlfriend, and wants Gordon to replace him with a trustworthier contractor.
Gordon wants no part of that, so the three of them, along with Mike (STEPHEN GEVEDON), a law student who's fascinated with the place since his father worked on a legal case involving a former patient, and Gordon's nephew, Jeff (BRENDAN SEXTON III), who's afraid of the dark, begin their work.
As the week passes by and the team members begin removing the materials, Mike listens to a series of taped psychotherapy sessions concerning a former patient who apparently suffered from multiple personality disorder. With the numbered sessions becoming more chilling as they progress, the team begins to encounter all sorts of odd occurrences in the old hospital, including the sudden disappearance of one of the crewmembers.
From that point on, and as the creepy events continue to unfold, the remaining team members try to finish their job, all while trying to figure out who or what's responsible for the bizarre occurrences.