Sgt. Ackland and P.C. Rickman are called to the flat of a prostitute named Allie after tracing malicious calls made from her phone, only to find her lying unconscious on the floor from a vicious assault. Turning her over, they find the words "join the club" written on her back. The case matches several other recent assaults on prostitutes, most of whom are being pimped by Robert Stern. Stern is apprehended, but although he attacked Allie he was not responsible for the calls she made or the writing on her back. Meanwhile, Ackland saves Beth, another of the victims, from throwing herself under a train. She explains that her attacker explained that this was the sinister meaning of the message. When the atttacker is eventually caught and brought back to the station, D.C. Rawton identifies him as her ex-boyfriend, Andy Marshall. A search of his houseboat turns up medication for the management of HIV. The malicious calls were being made to Marshall's estranged wife, who is pregnant and and unaware of his supposed HIV-status. A visit to Marshall's father reveals a history of faking medical conditions for attention. Returning to the houseboat, Rawton finds all the medication unopened, and with a completely different name printed on the label. She confronts Marshall, but he refuses to confess that he orchestrated everything including the phone calls to his wife. Andy is released without charge. It's too late to save Beth, who finally goes ahead with her suicide.
The episode's duration was 90 minutes.
- Trudie Goodwin as Sgt. Ackland
- George Rossi as D.C. Lennox
- Libby Davison as D.C. Rawton
- Simon Rouse as D.C.I. Meadows
- Gregory Donaldson as D.C. Proctor
- Karl Collins as D.C. Glaze
- Billy Murray as D.S. Beech
- Joy Brook as D.C. Holmes
- Tony O'Callaghan as Sgt. Boyden
- Suzanne Maddock as P.C. Rickman
- Andrew Paul as P.C. Quinnan
- Graham Cole as P.C. Stamp
- Jane Wall as P.C. Worrell