The team looks into the death of a terrorist 30 years previously after his daughter receives an anonymous note claiming he was murdered - an investigation that takes them right back to the Greenham Common anti-nuclear protests. Meanwhile, Sasha agrees to go for dinner with her ex-husband Ned, which he is hoping will lead to a reconciliation.

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.

The team investigate the unsolved killing of brilliant young doctor Lydia Dryden in a case that takes them into the two very different worlds of public and private medicine. Danny Griffin is bereft when daughter Holly leaves home to start university, so his UCOS colleagues throw some fun distractions his way. And he might even be about to acquire a pet...

Ted Case is welcomed by Danny and Steve into the UCOS office in Sasha's absence, but for all his wealth of experience, they aren't sold on his superstitious quirks. The team take a look at the case of a brutally murdered vicar who received racist hate mail in the lead up to his murder.

The boys' investigations take them to a lookalike agency whose top acts were found dead.

A young woman's paternity test leads to the reopening of a notorious murder case from the seedy underworld of 1980s Soho in which the prime suspect was mysterious ex-jazz chanteuse Angela Gold. Meanwhile in UCOS, feathers are ruffled when recently retired police officer Dan Griffin joins the team.

Family ties affect both Gerry Standing and Sasha Miller. While Sasha is forced to work with ex-husband Ned as he fills in for Strickland, Gerry returns to his roots in Bermondsey to help arrange his daughter's wedding. As a consequence he is thrown into a case involving the possible murder of an architecture student who is also the grandson of an old friend. Meanwhile, Danny Griffin has been on an FBI course in reading body language.

The team investigate the death of a personal trainer who had belonged to a Roman reenactment society and discover a gang selling illegal steroids, but the motive for murder may not be all it seems. And Danny Griffin starts to become attracted to his forensic pathologist colleague Fiona Kennedy just as he receives some troubling news about his wife.

When graffiti appears around London by an unknown person claiming to have murdered a celebrated street artist, the team reopens the four-year-old case. Originally part of a gang, the victim went solo when he received support from a wealthy art patron, leaving the detectives suspicious of his resentful former crew members. Meanwhile, Brian signs up to Twitter to chart the gritty life of a lawman, much to his colleagues' displeasure.

When Steve McAndrew's teenage son Stewie is arrested for drug possession, he finds himself face to face again with his ex-wife Tricia as they try to save the boy from a downward spiral. And after a distressed dementia patient escapes her care home to report a murder, the team look into the disappearance of a policeman, possibly murdered but missing since 1956...

UCOS want to talk to a Turkish girl who is found working illegally in Dalston, regarding a unsolved murder from 2009. The landlord of a pub, Richard Gibson, died in a fire and the case had remained unresolved. The team meet the landlady of the pub, Joanna Gibson, who is also Richard's widow. His best friend, David is also someone of interest, especially when the team find out the French champagne he is selling, is actually sparkling wine produced in Britain. Sasha enters the team into a 5-a-side football competition.

Ted leads an investigation into the apparent suicide of a city trader in the 80s.

With Sasha back on fighting form, UCOS investigate the death of a cricket prodigy.

Lane indulges his obsession with fishing when UCOS investigates the case of two boys abducted from a fishing lake in 1979, believing it could be linked to a recent spate of snatches near the M25.

The team investigate the art of illusion when they reopen a case involving a magic trick that ended in murder. Powerful mind games and hypnosis prove a dangerous mix for Brian Lane, however, sending him down a destructive path. Meanwhile, a session with the Magic Circle's Dr Moroni leaves a sceptical Gerry Standing feeling paranoid and his colleagues a little nervous around him.

As Brian Lane struggles to control and conceal his desire to drink again, he finds the perfect refuge in a commune at the centre of the team's investigation into the death of a university student. The case also helps Gerry face up to his relationship with Emily, who has not spoken to him since she discovered the truth about the DNA test at Ricky Hanson's trial.

When a retrospective exhibition of murdered fashion designer Ritchie Levene's work opens, the team is prompted to re-examine the three-year-old crime. The detectives learn about his tempestuous relationships with his new spouse, personal assistant and ex-wife Sarah, who believes his brother Adrian is the killer because he had the most to gain from his death. Meanwhile, Gerry enlists Emily to help update his image, although not everyone is impressed with the results.

When 18-year-old debutante Barbara Linden-Warner disappeared without trace 27 years ago, the assumption at the time was that she had been kidnapped and her father, a wealthy British arms manufacturer, paid a ransom for her return. When new evidence emerges about her last movements, the indication is that she may still be alive.

When cold-crime enthusiast Ellen Barker is murdered, a photo of Dan Griffin is found at her house. Griffin is interviewed by the murder team, who realise that Ellen was a friend of his. The senior investigating officer assigned to Ellen’s murder investigation is DCI Grace Mackie, one of Sasha Miller’s contemporaries from their Hendon training. Griffin is convinced that the last case Ellen was looking at could lead to her killer, and heads to Minchampton, where a woman called Sally Tunstall was murdered 25 years ago by local lad Dougie Haynes.

The team investigate when a skeleton is uncovered in the foundations of a swimming pool.

UCOS investigate the case of an alternative medicine practitioner bludgeoned to death.

When a camera and film belonging to a photographic lab assistant murdered in 1987 are found in a Soho pub toilet, the team reopen a 20-year-old case. Elsewhere, Gerry is less than happy when his daughter Emily joins the team and looks to Sandra as a role model.

After being released from jail, notorious paedophile John Davies admits to the abduction and murder of a child 25 years previously. Suspicious of his motives, the detectives reopen the unsolved case in an unusual attempt to prove his innocence, reinvestigating the boy's disappearance while on a demonstration with his left-wing activist parents. Guest starring Adrian Schiller (Being Human) and Samantha Bond (Outnumbered)

When blood-stained clothes belonging to Simon Belgrade, missing for five years, are uncovered in a London forest, UCOS find themselves trying to solve the conundrum of what seems to have been the perfect vanishing act. Standing finally faces up to a childhood fear, while Griffin is a comfort to Pullman as she passes a milestone and McAndrew makes a big decision about his son.

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.