Jessica Barnes is a young and idealistic psychiatrist who begins treatment for a new patient, Ronnie, a war veteran suffering from post-traumatic stress disorder, who is admitted to a recovery center isolated from everything. During an outbreak, one patient attacks another violently. The situation gets even worse when other patients as well as clinic staff begin to be mysteriously killed, indicating the presence of a serial killer at the scene. When everyone suspects Barnes's patient, it will be up to her to discover the truth while trying to survive.