A two-year-old girl is abducted from her home and her dysfunctional family comes under immediate suspicion, but then a convicted child killer is also connected to the case.

Jack and Charlie's hunt for a serial rapist becomes complicated when the latest woman to be attacked turns out to be Diane Ackerman - the wife of the station's chief superintendent Howard. A routine background check reveals that the police had recently been called to their address and Diane has a bruise on her throat that predates the rape.

Euthanasia campaigner Terence Holland is found unconscious in his penthouse flat by his doctor after an apparent drugs overdose, leading to the assumption that the terminally ill man had found someone to help him die. However, evidence at the scene prompts Martha to speculate that this could be a case of attempted murder.

Jack and Charlie are called out in the early hours after a 13-year-old girl is stabbed. The hospital reports back that she was eight weeks pregnant, shows signs of possible self-harming and had been previously sexually assaulted, while a number on her mobile phone belongs to the cab driver who drove her to hospital and claimed he did not know her.