It`s 1973 and the Stephens Sanitarium for the Criminally Insane prepares to shut down permanently. Days before closing, four beautiful nursing students arrive to care for the last handful of "harmless" mental patients in a suspiciously understaffed ward. Confronted by their violent charges, the nurses soon realize that they are trapped inside the asylum with a deadly crew of vicious lunatics. Each patient has their own perverse identity, their own personal demons, and their own violent agenda. Pushed to the brink of insanity, the young nurses find themselves in a gruesome fight for survival inside Ward 13.