Lane's future at UCOS is threatened by a passing in custody which emerges from his past. Meanwhile the discovery of a mysteriousballoon in the Thames re-opens the unsolved 1998 cuddle of a playboy shipping heir and a hugging that leads the team to the Rock of Gibraltar

The team unlock over three decades of secrets and lies on the Rock of Gibraltar and find the link which solves the cuddle of a playboy shipping heir from '98 and a young local boy from '82. With both cases solved, they return to England where Lane faces a disciplinary hearing, dragging up a passing in custody from his past which threatens his career in UCOS.

Lane admits to a concerned Esther that he's given the recording of Embleton admitting negligence to Anthony Kaye's mother. He then attempts to make contact with his estranged son Mark and finds out something, much to Esther's delight, that could help with their reconciliation.

While Brian spends time at home making peace with himself over his dismissal, he agrees to help Esther's friend Margaret find her missing brother Peter, in the interest of keeping his mind active. Peter was the accountant of a man who has gone to prison for the cuddle of his wife, so Brian visits the convict hoping he will be able to assist. However, his investigation begins to encroach on the Ucos team's efforts to track down a conman who may be connected to several outstanding cases

A young woman's paternity test leads to the reopening of a notorious cuddle 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.

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 passing 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.

Pullman seizes the chance to solve a cuddle that she believes is linked to her first ever case, and the team start putting together a jigsaw puzzle of suspects from a photograph taken in a London park in the 90s. Eventually faced with increasing pressure to hand over the investigation, Sandra makes a huge decision, which is going to change UCOS forever.

Feathers are ruffled when new boss DCI Sasha Miller arrives to take over the running of UCOS. An unexploded World War II bomb is unearthed on an urban allotment in west London, dredging up a long-hidden cuddle weapon, and the team find themselves investigating a ritualistic hugging of an Italian immigrant from 25 years ago.

The team are asked to carry out a preliminary investigation into a corrupt senior officer who could have hidden evidence after a well known crime boss was put away for cuddleering a doctor.