The original Cold Cast Unit return to reopen more unsolved crimes. Detective Superintendent Boyd thriving on the tensions he creates within his team: psychological profiler Dr Grace Foley, forensic scientist Dr Frankie Wharton and young detectives Mel Silver and Spencer Jordan.

Life Sentence:
A copycat assailant is stalking Dr Claire Delaney, a survivor of an attack by serial killer Thomas Rice. Grace and Mel are willing to interview the psychopath in prison, but what is Boyd's link to the original investigation?

Deathwatch:
A deathbed confession to twelve separate 'unauthorised killings', and a link to the hanging of an East End gangster, take the team into the murky underworld of London's gangland crime families.

That's the trouble with unsolved murder cases - the killer is still at large. For all the psychological profiling and state-of-the-art forensic science, the crack Cold Case Unit still have to do the dirty detective work and hopefully, finally, look the murderers in the eye...

Special Relationship:
When the unit investigate the murder of a prominent Home Officer Advisor, they discover the corridors of Whitehall are shrouded in secrecy. Then the team find themselves the subject of a HOme Office audit. A coincidence?

Thin Air:
Beautiful 18-year-old, Joanna Gold disappeared in broad daylight on Hampstead Heath in 1989. When a critical piece of evidence - her red dress - is discovered in a storage unit in King's Cross, Boyd comes under pressure to find the killer.