A young woman, Marina sets fire to an abandoned car in a street and takes photographs of it as it burns. Boyd walks by and tackles her to the ground, attempting to shield her from the possible explosion. He later learns that Marina's father died in a car accident a few years earlier in that spot, and Marina refuses to accept that his death was an accident.

Although not officially a cold case, Boyd is intrigued and reluctantly agrees to investigate. Frankie runs forensic tests on Marina's father's car and proves that he was still alive after the crash and could have escaped. The answers they uncover may mean that the danger to Marina is much greater than any of them had suspected.

Boyd has Marinas uncle, Mike Coleman and her mother Gwen brought in for questioning while Frankie searches the house. The team find the items that were recovered from the car nine years ago and suspect that Perry Coleman was being blackmailed by Rod Brogan, a friend of Perry's. Boyd has the body exhumed and the DNA results surprise everyone.

The Cold Case team is forced to enlist the help of a psychotic serial killer named Thomas Rice, AKA "the Gambler" (because he left playing cards at the scenes of his murders). The one woman who escaped death at his hands, the cool and poised Dr Clare Delaney, gets a dreadful reminder of her past ordeal and a fearful shock when a playing card is flung at her car windscreen as she sets off to make a house call on a wet, windy, dark night.

The team look again at the Gambler's crimes, prompted by Boyd's unshakeable belief that Rice had claimed other, hitherto undiscovered victims.Boyd - who has personal links to the case - and Grace decide to use detective constable Amelia Silver to lure a confession from Rice.

Boyd and the team continue to begrudgingly rely on serial killer, Thomas Rice's assistance on the case, while also trying to protect Dr. Delaney from experiencing her terrifying ordeal once more at the hands of the copycat assailant.

It becomes apparent that he might have help on the outside, so it's crucial that Boyd confronts one of Rice's intended victims, Dr Delaney, to find out what went on during her captivity. Why did he spare her life?

Twelve years after Joanna Gold famously disappeared in broad daylight on Hampstead Heath, the dress she was wearing is found in a lock-up. The team begin the hunt for her killer.

While under pressure to discover the truth behind the murder of young Joanna, DCI Boyd (Trevor Eve) slips up and makes possibly some irreversible mistakes.

Joanna's killer begins stalking her sister.

After they get a tip off in an anonymous e-mail,the team head to a waste ground in east London, where they find the remains of a right-wing fascist activist.

When they do some digging into the man's past, they discover the deceased was not who he claimed to be, but in fact he had a hidden agenda of his own.

After a woman is discovered stabbed in the eyes and incinerated in her car she is identified as Claire Somers, a neglected child who was taken into care, then later kidnapped in 1986 at the age of seven. Robert Fenchurch had his eyes stabbed out on the night Claire was kidnapped as her abductor fled the scene. The team soon find out that Claire had snatched 15-year-old Abigail Harding, who was found locked in a hotel room.

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?