Dempsey pretends to be dead and goes into deep cover after he gets a message that Coltrane knows where he is. Makepeace is his contact. But even while posing as Johnny 'the Wolf' Lupino, Dempsey can't keep his nose out of police business and gets close to American gangster Mara Giardino.
Dempsey is losing himself in the part of Johnny Lupino as he gets ready for a gold heist organized by Mara Giardino. Unknown to him, his arch enemy and former boss Coltrane is closing in on him. A worried Makepeace is captured by Mara's men while tailing her partner. And Dempsey begins to fear he may be about to lose another partner.
While on their way to Chas Jarvis' wedding, Dempsey and Makepeace foil a bank robbery. Even though this crime is being handled by another department, Dempsey can't let it go and ends up being framed and on the run himself.
Dempsey and Makepeace find the broken body of a bare-knuckle prizefighter on the street carrying counterfeit money. Posing as an American couple named Dwayne and Lu, they manage to get into the illegal underground fight. Meanwhile Mrs. Spikings forces her husband to have his men search for her stolen car.
Shipments of army weapons are being hit systematically. An eyewitness points Dempsey and Makepeace towards an ex-army man called Jimmy, but their superior Edwards insists they go after dimwitted strongman Big Ben Davis instead.
Eddie Dean kidnaps a young girl to keep her mother from testifying against a crook named Burton. Dempsey and Makepeace seek help from the one man able to find Dean: Dempsey's nemesis Keith Lymon. But first they have to get him out of prison and convince him to help.
SI10 is hunting for the so-called 'Thriller Killer', who kidnaps blue-eyed brunettes and kills them within 20 hours. But the killer takes an interest in Makepeace as she and Dempsey get close during their investigation and demands to meet with her one on one.
Makepeace resigns from the police force after having a vision of Dempsey being shot dead. While she begins working on a dinosaur exhibition at the National History Museum, Dempsey is partnered with Joyce Hargreaves, who has been desk bound for the last several years.