It's a busy day on the station front desk, and P.C. Smith fails to notice that someone has left a hold-all next to the desk. When it is discovered, Insp. Frazer orders the station evacuated as a safety measure while the bomb squad is called in. Sgt. Cryer and W.P.C. Martella have trouble getting a violent female prisoner into and out of her cell. D.C. Dashwood winds Smith up about not noticing the bag, and he conducts an interview with a suspect in a car. P.C. Edwards is acting oddly, arguing with W.P.C. Ackland and he keeps returning to the station looking for something. SO13 find an incendiary device in the bag, but it explodes, blinding an SO13 officer.

Sun Hill police are being called out to a series of bogus shouts which the Yard pins down to a computer hacker breaking into the police computer network. Sgt. Cryer investigates, and finds a former university student who has a acquired an ex-MOD computer which still had access codes to government and police networks on the hard drive. W.P.C. Ackland checks in with a woman who is too scared to leave her flat as she has been repeatedly mugged. Ackland convinces her to go out to get some cigarettes, but when they return, her flat has been trashed. June arranges for her to be moved off the estate. Roach, Dashwood and Carver watch as a car is pulled out of the river with the body of a young woman inside. They question the car owner who had reported it stolen, but he is clearly hiding something. D.S. Roach must inform Sgt. Cryer that it was his son, Patrick, who was driving the car when it went into the river, and that he'd left the scene.

D.S. Roach goes to the hospital to talk to a young man who was slashed in the face with a knife - the fifth is a series of ""steamer"" attacks, where knife-wielding youths have held up restaurant patrons. D.C. Dashwood receives a tip-off about the steamers' next target, and the restuarant is filled with undercover police officers. P.C. Edwards is jealous that he and Carver didn't get a free meal paid for by the Met, and the steamers are caught when they raid the restuarant. P.C. Melvin investigates a strange smell from a flat used by junkies, and finds the body of an elderly man who suffered a heart attack. Melvin can't believe the old man was a junkie.

Sun Hill C.I.D. and the Vice Squad raid six flats to catch a pornography ring. All the flats are clean except one, and it is suspected that the targets were tipped off. D.C. Dashwood saw D.I. Burnside making a phone call just before the raid, and shares his suspicions with D.S. Roach who wants nothing to do with it. Dashwood informs Ch. Insp. Conway, who calls Burnside in. Burnside insists he was calling his travel agent, and Conway checks up on it. P.C. Smith and W.P.C. Ackland pull over a car for dangerous driving, and the driver is one of the suspects in the raid. He helps Burnside catch the head man, Collins, who puts Sun Hill in the clear for the tip-off, but Burnside warns Roach he'll find out who grassed him up. Smith and Ackland stop a man from filling another man's skip with rubbish. When the dumper fails to collect his rubbish, the skip owner dumps it outside the station.

Cryer is filling up a car. Peters gives the relief a lecture about refilling area cars after using them. The fraud squad are visiting the station a day early. CID has Customs and Excise visiting. Peters and Haynes are told of a man who had a heart attack. The ambulance leaves before his belongings can be handed in which results in a complaint being laid. Burnside interviews a boy racer that Viv has arrested.

Tosh and Grieg investigate a death in a hotel. The manager treats them like scum. Man was a Polish travelling tie salesman and died of a massive heart attack. Reg pulls out 7 different addresses for him from the files. 4 wives turn up (separately). Hollis gets snapped at by Brownlow who won't let Reg get all the time off to attend a federation conference. Conway wants to see Ramsey about a missing keyring and Stamp about accidents in the area car. Claire and Ken are investigating locked fire doors at a bingo hall when they walk into an armed holdup.