Creegan returns from psychiatric sick leave to clear a killer he helped convict. But the local police chief remains convinced the man is guilty-especially since the murder spree resumes after his release. All victims to date are married women with their hearts neatly cut out and left nearby in garbage bags.
Creegan, Taylor, and Rivers step up their pursuit of the "garbage bag" killer with the discovery of yet another mutilated female corpse. Creegan concludes the slayer doesn't hate the women he's murdering; he's targeting the men who are left behind. The killer's final mark hits much closer to home.
The discovery of a charred body in a derelict institution triggers off a hunt for a serial killer using fire as a weapon of death. Creegan is declared fit to return to work after his harrowing experience in Northumberland, and is reunited with Taylor to investigate the case. Enwright introduces a new recruit to the OSC, while Creegan offers comfort to Rivers' bereaved fiancée.
Another charred body is discovered in a nursery school. Matt Van Der Twest, the Hyndman House arsonist, is interviewed, but Creegan and Taylor are convinced he is innocent of the recent murders. Then the chance discovery of a child's drawing brings Creegan closer to the real killer, but not before one last victim is claimed.