The time is 1988. A VA psychiatric hospital is experiencing a wave of mysterious deaths among its patients. Deaths are often labelled as heart attacks, yet many patients have no cardiac history. Tom Callahan, an ex-cop, is hired as an aide and then told to keep quiet about his past. Soon he is working undercover in their medical ward. One night a box of hospital records meant for the dumpster ends up on his back seat. The records reveal a coverup at high levels in the hospital and the existence of a nurse who was present at 90% of the mysterious deaths. When Tom probes into her past, he discovers that a much-loved nurse who once killed for mercy, now is killing patients to get a night off. Soon his cabin is torched, and he is a fighting for his life and the lives of his patients.