'Cold Blood', originally transmitted on ITV, 31 December 1987
Written by Glenn Chandler, Directed by Haldane Duncan

Ruth Wilson shoots her husband, George, as he sits in his car outside the Scottish Exhibition Centre. She is found by the riverside holding the gun. Interviewed by DI Taggart, Ruth says she has no regrets: George was having an affair with Geraldine Keenan, manager of the Aqua Health Club, which he owned, and wanted a divorce. An autopsy, however, shows that George died before he was shot, from a stab wound. Scratches on George's wrist indicate that his watch was ripped off. Donny, a tough-looking young man, sits in his bedroom rifling through George's wallet.

Ruth is released. Taggart asks about the missing watch. It was a gift from a former snooker professional, Ricki Keenan - Geraldine's brother - who George used to sponsor. George lent Ricki money to open his own snooker club, though the loan was never repaid.

Donny mugs a driver on the A47. Taggart visits the Aqua Club, where he notices a Chinese birthday card addressed to George. Geraldine angrily denies any affair with her boss. At Ricki Keenan's snooker club, Ricki's mother tells Taggart that her son bought a cottage by Loch Lomond instead of paying George back. Ricki claims to have forgotten what the watch looked like. Jardine learns that Superintendent McVitie's wife, a client of George Wilson, saw George and an Oriental woman together. Remembering the Chinese birthday card, Taggart makes Jardine search a rubbish bin to find it. The card was sent by a woman called Lin Chang.

Donny approaches Ricki, offering to sell him George's watch. Ricki declines but, recognising the watch, follows Donny to a fairground. He joins Donny on the Big Wheel and offers to buy the watch. Donny tries to borrow Ricki's paper and his concealed knife falls out. They struggle, and Ricki shoves Donny to his death. Taggart arrives and refuses to believe Ricki's defence that Donny attacked him.

Lin Chang tells Taggart that George was her student. Ruth and Ricki, he discovers, were lovers, and planned George's murder together. To confuse the investigation, Ruth returned to the scene and shot her dead husband, but was mugged by Donny before she could dispose of his belongings. Ricki had been hunting Donny ever since.

Taggart tracks down Ruth and Ricki to a high bridge overlooking Loch Lomond. Ruth tries to run him down in Ricki's sports car, but hits Ricki instead, sending him hurtling off the bridge.