By day, nurse Abby Russell (de la Huerta) lovingly attends to the patients at All Saints Memorial Hospital; by night, Abby prowls nightclubs, luring unfaithful men into dangerous liaisons. After Danni, a young, sensitive nurse, joins the hospital staff, Abby pursues her friendship. But when the friendship turns to obsession, Danni spurns Abby, unleashing Abby's fury and a rampage of terror.