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?