Jardine and Reid investigate a killing in a country house swimming pool. One of the victims is Rick Mulvey, former lead guitar of the 60s pop group, the Adders. Their vocalist died while on tour 25 years ago. Ian Garvey, Kate McCready's boyfriend is savagely beaten by two bouncers, and the following day, he is knocked down by DC Reid in her car.

When a clever lawyer gains an acquittal for his client on an apparently straightforward murder charge, the team are compelled to restart the investigation from scratch – but then the killing starts again. A petty thief tries to plea-bargain with some new evidence in the case, while Reid uncovers a blackmail scheme which may have led to murder.