W.P.C. June Ackland's father is dying in hospital. P.C. Taffy Edwards is given traffic duty after arriving late for parade. P.C. Jim Carver gets beaten up in a bus queue. Sgt. Cryer and P.C. Patel investigate an alleged rape. Insp. Kite is set up and sent to collect mud samples because of a suspected radioactive leak.

Ackland and Quinnan investigate when a family are strangely silent about the death of their landlord.

DCI Jack Meadows introduces new DS Claire Stanton to the rest of the CID team, who are jealous when she manages to land an eco-terrorism case on her first day. Someone has been injecting mercury into oranges as a protest against GM foods. Security footage shows a 'New Age' couple lurking around the fruit section, but when they are questioned, it appears they were stealing oranges rather than contaminating them. Supermarket shelf stacker Darren matches the description of the perpetrator, and when challenged, he incapacitates DC Proctor and takes him hostage. Locating his flat, the police find Proctor alive and well, but then word comes through that Darren is in the children's ward at St Hugh's armed with a gas grenade. SO19 arrive at the hospital, but DS Stanton manages to talk Darren into giving himself up.

Page and Hayward attend a disturbance at a pub and find the landlord and one of his regulars being beaten up by three masked men. Meanwhile, Stamp, Quinnan and Klein attend the scene of a second beating, another three masked men attacking local villain Frank McBride outside the back of his club. Realising the incidents could be connected, Hayward investigates, and discovers a turf war between two rival gangs of cigarette smugglers. As the evidence against the two rival firms stacks up, Klein finds himself in trouble when he tries to buy a mixing desk from his favourite DJ, Johnny Margolis, and ends up abducted by the McBride gang, but a freak accident leaves Tony McBride dead and Klein seriously injured.

After noting Klein missing from morning parade, Quinnan and Stamp find him unconscious and badly injured in the back of the crashed van belonging to the now-deceased Tony McBride and his cigarette smuggling gang. With McAllister determined to prove that Klein is corrupt, Boyden and the relief race to find evidence to clear his name. As Klein continues to recover in hospital, Hayward suspects that missing DJ Johnny Margolis may seem to be the key to the whole mystery, and he is found trying to escape from three thugs. Boyden searches McBride's house, and an obbo is soon set up to catch the cigarette smugglers red-handed. Boyden is stunned when he works out who is responsible for the smuggling ring.

Boyden attends the scene of an RTA involving an HGV and discovers fridge/freezers with holes in bottom. Stamp and Quinnan come across a group of men wandering away from the crash, however only one is arrested. Upon his arrival to custody, he asks to speak to Conway, revealing he is an immigration officer from France and he was onboard the crashed truck with a group of immigrants.

Page and Quinnan pose as a married couple running a hotel, while Carver and Hollis, and immigration agent Petrit, pose as their employees. Stamp continues his undercover role as an HGV driver for the firm bringing in the illegals, while Webb, Lennox and McAllister maintain surveillance on the hotel. The hotel is busy preparing for its opening night, and when the temporary staff arrive, Quinnan seizes the opportunity to attract Berisha's attention by ringing the agency and complaining about them. Later, Stamp makes a delivery to the hotel – four refugees who are immediately set to work. He then picks up his boss Kerns and drives him to a lorry park, where he finds twenty scared refugees and a decomposing body.