Sergeant Stone finds a bag of cocaine in the boot of a stolen limousine and learns its original driver, Dave Latham, has been beaten up. At Dave’s house, Inspector Gina Gold finds his wife, Danielle, unconscious. Elsewhere, DS Stuart Turner’s driver Trevor Jones claims there’s a rumour about someone using limos to deal cocaine.

Over at St Hugh’s, Danielle identifies her attacker as Lloyd Carter, who confesses that Piers Halston, Dave’s boss, paid him to beat her up. At a meeting organised by Trevor, Dave admits to Stuart that he had been ‘watering down’ coke to make money and when Piers found out, he sent Lloyd after him and his wife.

When it transpires that Piers deals drugs through a car valeting firm, DC Mickey Webb goes undercover as a city banker to order a limo with drugs included. With the other officers waiting to storm the valeting firm, Mickey realises that Piers is onto him…