The team reinvestigates the unsolved murder of 23-year-old Maureen Mulcahy of Port Talbot; after a major breakthrough, the team identifies a new prime suspect.

The team investigates a case from 1959, in which a quiet Cardiff community was devastated by the abduction of six-year-old Carol Ann Stephens, last seen getting into a car with a mysterious, dark-haired stranger.

The team finds a vital new clue in the case of Muriel Drinkwater, who was brutally murdered near her home in 1946; her death has long cast a shadow over this corner of Wales.

Three trunks, two murders, one man in the frame.