Sgt. Bob Cryer is approaching his 30th year of service, but some of the senior officers at the station doubt he is still up to the job. Supt. Tom Chandler assigns Bob the difficult task of resolving a situation where a group of prostitutes are at loggerheads with a local residents group led by Councillor Angela Morris. Bob suggests a 'zone of tolerance', a non-residential area where the prostitutes can work without upsetting the locals, and manages to convince the girls to give it a try. As Tom heads off to a charity dinner, a call comes through that the Morris's house has been torched.
Meanwhile, PC Dale 'Smithy' Smith attends his interview for transfer to SO19. He is successful, and leaves Sun Hill to join the Armed Response Unit.