Season 21

Hospital Dr. Mellor is attacked by a masked assailant carrying a syringe full of lethal drugs, but manages to survive the attack. He points the finger at rival doctor Thomas Finn, but Finn has an alibi. The next day, Mellor is found dead, but again Finn has a cast-iron alibi. Was Mellor correct in his suspicions? Or is Finn in fact entirely innocent?

The Houston family are returning from a funeral when they discover the body of a taxi driver in his car outside the family business. Burke investigates and discovers a link between the victim and the daughter who has just been buried after an overdose. Suspicion falls on the father, Davie Houston, who appears to be involved in money laundering.

Burke's professional life is left hanging in the balance after the body of a librarian is found behind the wheel of a car in the Clyde after an apparent hit and run. The detectives are baffled, it appears that the victim had been tied up and was already dead before the car hit the water. But certain allegations are made about Burke which hinder the investigation?

Robbie is all set to spend a romantic weekend with his new lady love Eve Hamilton. Unfortunately, the mood is soured when the corpse of a young man, a photographic assistant, is discovered at the romantic hideaway. Investigating the boy's death and subsequent others, Robbie begins to discover that Eve is perhaps not as innocent as she would appear.

When the body of 21-year-old medical student Amy Penn is found by children in a park, the team prepares themselves for a difficult investigation. Heavy rain has destroyed any evidence of her killer, but strangely her body has been sculpted in death into a childlike pose with her thumb in her mouth. Initial enquiries uncover few leads.