In the early 1990s, a number of seemingly healthy children, entering hospital for minor ailments, begin to die; suspicion falls on a young nurse, Beverley Allitt; survivors and detectives revisit the early investigation of the nurse.

Investigating the child-serial-killing nurse dubbed "The Angel of Death" and her vicious crimes; using her police interview tapes, a portrait of the psychopathic killer emerges.

As the police continue to question Beverley Allitt over the murder of four children, the initially friendly and helpful nurse starts to show the investigators her true face.