The Cold Case team is a crack squad of police investigators who reopen unsolved murder cases, using new technology to re-examine evidence that hopefully will lead to the killer. They are at the cutting edge of modern police investigation, but they have been given just one year to prove their worth.
Boyd has to break in a new team member of equal rank, Detective Superintendent Sarah Cavendish, a high-flyer recently grounded by a hushed-up failed operation. The team investigate the mystery of a missing banker to help the man's seemingly cursed family find closure.
Boyd is convinced that the missing Donald is not a murderer, and pushes his team to try to make sense of all the vague connections in the case and eventually confront the unfathomable evil lurking within the heart of this sad, unfortunate family.
When the Cold Case squad learn that a recently murdered woman is Claire Somers, who as a seven year-old girl was abducted from a care home 25 years ago, they unveil a shocking portrait of life in the 1980s care system.
The investigation into Claire Somers' death has seemingly unleashed a predator straight from the darkest childhood nightmare. But are they looking for a monstrous child-stealer, or misguided saviours?
The Cold Case team investigate the murder of notorious Falklands' veteran-turned-peace activist Piers Kennedy, rumoured by conspiracy theorists to have been killed by the state - a theory that appears far from outlandish when his corpse is discovered in tunnels directly under the MoD.
As Boyd and his team burrow deep into the paranoid, polarized world of early 80s British national security, they uncover duplicity and sabotage that goes to the heart of government today, and that puts Grace in mortal danger.
When a missing medical student's DNA matches with that of an unidentified corpse found tortured and drowned years before, Boyd suspects a cover-up. Unmasking the fears and tensions of the post 7/7 terror attacks, the team discover the cold case victim could have formed part of a terrorist cell.
Boyd needs Sarah's counter-terrorism expertise to help expose the state's involvement in Karl Barclay's death, but the case only amplifies Sarah's crippling self-doubt and guilt over the death of a colleague.
Boyd is being moved out of the Cold Case Unit, but first he decides to take on the unsolved mystery of 16 homeless boys from Waterloo Bridge who disappeared in the 1980s. The Cold Case team's investigation unearths the grimmest find of their careers.
There's growing concern amongst the team over Sarah's disappearance, and time is running out for Boyd as he fights his final battle for justice against a powerful adversary. Will he prevail?
