Deputy Assistant Commissioner Robert Strickland is the new boss in charge of the Unsolved Crime and Open Case Squad (UCOS). He asks the team to look into the death of David Barrie, a top barrister found in his car in 1980 after being bound and gagged.

Luck turns against Standing when he loses a poker game, owing bookie Michael Jacobs £10,000. But Michael offers him a chance to clear his debt by finding out what happened to his dad Joe, who died after being mugged outside Walthamstow stadium in 1983.

The Home Office pathologist asks the team to identify the remains of an unidentified woman, whose remains were found back in 1987. These remains are the only body that he was unable to identify. With his help and that of his attractive assistant, not only must the team identify the body bits, but how she died and who killed her.

The murky death of Joe Walsh, General Secretary of the Crane Driver's Union, whose body was found in the Thames in 1975, is reinvestigated. At the time of his death, Walsh stood accused of stealing money from the union's account. The team find themselves at the centre of a political minefield, with suggestions of misappropriated union funds, MI5 involvement and a union leader whose threats of strike action were gravely threatening the national interest.

The vicious criminal Chopper Hadley, who has been back in the country for a week, is searched for by the team. However, Halford is viciously intimidated and the squad start to realise the full danger of their target. Desperate measures are used and Brian is sent undercover to get Hadley once and for all.

A young woman insists that the suspicious death of a local librarian was because of witchcraft and the team are drawn into the world of magic and the supernatural. A series of strange events occur and they are put under increasing pressure. The squad gets convinced that the supernatural exist and struggle to remain cynical.

Ray Cook, a legendary criminal has turned prime time celebrity. The team set off to find him, because there was a notorious bank job which left a cashier dead. He is a suspect, but was he responsible, or is he as innocent as he claims?

The team are on the case of the ice cream bandit, an armed robber who's targets were the ice cream vans of two feuding ice cream manufacturers in the mid 1990s. The battle between the two families erupts into violence, so UCOS decide to track down the bandit and stop the conflict once and for all.

Pullman struggles to keep the boys in line as their chequered pasts begin to be revealed. Halford is determined to nail a vicious criminal who has so far eluded him and in doing so he puts himself in grave danger. Standing receives a surprise visitor which shocks him. Pullman is increasingly frustrated and weighs up an opportunity that could end her time in UCOS.

The future of the team is threatened and without having that to deal with, Sandra has to take drastic measures to prevent Jack from exacting revenge against the man who killed his wife Mary. Sandra also has the added benefit of trying to keep Jack’s actions from shady new recruit DCI Karen Hardwick while working on a 10-year-old murder case.

Sandra's private and professional worlds become intertwined when her mother has a fall and goes into a care home - but the establishment is revealed to be a scene of a suspicious death a year earlier.

When an armoured van is discovered at the bottom of a lake, the team makes a link with the murder of a women 17 years ago.

The team reinvestigates the 1950s murder of a young wages clerk at Battersea Power Station.

Richard Dunne was hanged for Frederick Tully's murder, but his granddaughter, Hannah, is waging a campaign to have Dunne posthumously pardoned.

The discovery of a suitcase containing used fivers in the attic of the Tully home sheds new light on the case, revealing a possible blackmail plot.

A trace on the used fivers reveals that they should have been destroyed in the Battersea Power Station furnaces back in the 1950s, but were actually being saved by Douglas Murray, a friend of Tully's.

It also becomes clear that the Battersea furnaces were being used to destroy other sensitive documents as well as used bank notes.

When the team discovers a classified document relating to a massacre of civilians carried out by the British Army in Kenya, they uncover a blackmail plot spanning more than 50 years.

When Brian's dog finds a body, it prompts two people to confess to murder. It turns out that the body is over 600 years old, so Sandra, Jack, Brian and Gerry must discover why the pair took responsibility for a crime they couldn't possibly have committed and if they are the perpetrators of other killings.

Elsewhere, Strickland is rather keen for them to solve an even more tricky mystery that is closer to home.

Gerry meets his heroes, the 70s rock band Bad Faith, when the team investigate the death of its lead guitarist. It is over 30 years since the group split up, however, and the ageing rockers do not quite live up to the legends Gerry remembers.

Meanwhile, determined to prevent UCOS from disbanding, Brian finally tracks down Jack and tries to persuade him to return.

New series of the drama featuring an eccentric group of ex-police officers brought out of retirement to investigate unsolved crimes. Jack confronts his nemesis in court when Ricky Hanson stands trial for his attempted murder, and Gerry faces the consequences of lying to his 'daughter', Emily. The team uncover a shady organ-donor racket when they reinvestigate the murder of a wealthy businessman who left a three million pound fortune to a prostitute.

The team return to the 1992 case of actor Michael Austin, shot dead by his wife on stage during the opening night performance of Death at the Masked Ball. Already a man down when Halford goes AWOL, the case looks like claiming another member of the team as Lane embraces his newfound love of acting and the theatre.

The team reinvestigates the murder of a popular DJ who died live on air after an arson attack at 80s music station Roxy Radio. Lane is determined to find the missing Jack Halford when Pullman and Standing threaten to quit rather than work with a new team member.

When the gun used to murder a talented young boxer 11 years ago surfaces in an armed robbery, UCOS are drawn into the darker side of professional boxing in a case that causes conflict and friction among the team.

The team reinvestigate a 30-year-old safety deposit robbery, and they soon find themselves being drawn into a case involving police corruption that threatens the future of the UCOS itself.

When the team investigate the death of an MP's researcher and find themselves in hot pursuit of a mysterious Bosnian woman, Strickland introduces Pullman to a war crimes prosecutor who proves to be more than helpful to their case.