An out-of-control teenager attacks her mother in an emergency room. While upstairs, a nurse is stabbed to death on an inpatient psychiatric unit. The murder suspect, a seventeen year-old-boy with schizophrenia becomes catatonic. Enter Dr. Molly Katz, a senior psychiatric resident and mother of two who, in an attempt to understand how she missed murder in the mind of her patient, gets drawn into the dark world of kids gone bad--really bad.

Through Molly's eyes we track the steps of a killer from the streets and suburbs of Boston to the wards of a hospital for the criminally insane. As Molly struggles to free a boy from psychosis and the threat of prison, the killer's thirst for blood grows and his eyes turn to Molly and her children. It's nature versus nurture at its wildest as we face the ultimate question: Is evil learned or can a child be born without a soul?