The new and unusual case for Detectives Brock and Poole - One Saturday night, a masked gunman walks into a jazz club and murders the drummer. Very soon, Detective Chief Inspector Brock and Detective Sergeant Poole find themselves taking an interest in the guests at a party in Surrey's stockbroker belt, which leads them to look again at a five-year-old robbery and to interview a dozen or so armed robbers. The killer is eventually arrested, but not before numerous extra-marital affairs come to light and a bullion van is attacked.