As he and PC Quinnan investigate a burglar alarm, PC Eddie Santini sees Jessica Orton meeting covertly with Ferguson. Making excuses, Santini borrows the panda car and races to the Ortons' club where he confronts Jessica. As she storms off, there is a huge explosion. Santini is shocked when one of the officers assigned by AMIP to investigate the explosion is his old nemesis, DS Rosie Fox. Fox is suspiscious of Santini's involvement, but her colleagues put it down to the animosity between them. As Santini returns to his flat, where his lover PC Vicky Hagen is waiting, he is kidnapped by Ferguson who assigns him the task of picking up a consignment of drugs from Amsterdam.

Jessica Orton is brought in for questioning, but is released without charge. When she returns home, PC Santini is waiting for her, desperate to know if she grassed him up. They fight, and Santini hits Jessica, knocking her down the stairs and killing her. Realising her house is being watched, he escapes out the back. Vicki Hagen finds a set of keys under Santini's bed which she brings to the station to return to him.

Vicki Hagen finds Eddie Santini's tickets to Amsterdam, and questions him about them, but he is evasive. DCI Pallister takes DS Fox off the Jessica Orton case after her accusations against Santini, but she decides to do some investigation of her own. Santini, meanwhile, acquires a gun and some Class-A drugs to plant in Ferguson's boss's house when DS Timpney and the Area Drugs Squad raid it. Fox stumbles upon the house and is captured by Ferguson. His boss Mr Sherman is displeased that Santini allowed a police officer to find them. When Area Drugs arrive at Sun Hill for the raid, CID realise that both Santini and Fox are in trouble. Sure enough, Ferguson's radio scanner warns him of the forthcoming raid and he locks Santini in the same room as Fox. The two argue, but are pulled apart when Santini attacks Fox. She manages to escape, and Sherman's men are intercepted by SO19. Back at Sun Hill, Fox realises the keys in Hagen's possession are Jessica Orton's - and she arrests Santini for m