Risk factor

"When they found the nurse she was already dead. Sitting next to her body, covered in blood and holding a knife, was seventeen-year-old Garret, a patient in the psychiatric ward of the hospital. Dr. Molly Katz can't believe it. She's Garret's doctor and she never thought he was capable of anything like this. But now a second nurse has been butchered. Who's stalking the hospital corridors for prey? Could it be Garret after all? As Molly fights to...