The team investigate when the family of Richard Dunne, one of the last men to be hanged in Britain, say he was the victim of a miscarriage of justice due to police corruption.

After a bent detective is discovered on the force, the UCOS team is tasked with investigating his only unsolved case. In 1998, assistant brewer Graham Thompson was found drowned in a vat of beer at Felspar Breweries. The dead man's girlfriend has always maintained that it wasn't an accident. Everyone concerned, including Sir Freddie Felspar ,says he was a brilliant brewer and a great loss. The original investigator failed to interview either of Sir Freddie's children and son Julian is now the company's Chief Executive. The brewery had won the gold medal for its beer 5 years running but in 1998 they lost to a small brewery that made its reputation on the win. The team now wonder if industrial sabotage may be at the root of the mystery. Meanwhile, Sandra continues to investigate her late father's activities while he was on the job.

Ex-actress Gloria Gransford draws the team's attention to a clip, posted on the Internet, from a film she made in 1990 called 'Shadow Show', after which the producer Max Stone was stabbed to death and leading lady Eva Roderick disappeared. Director Don Maddox, Gloria's ex-husband, is egotistical and evasive, and the only other surviving crew member from the film - who posted the clip - is found dead. His young boyfriend goes on the run and located Eva, who now has a new identity. A siege situation develops, which Brian defuses.

When keeper Zac Halsey's corpse was found in the tiger enclosure at Harefield Zoo in 2006, the assumption was that he had been mauled to death, but blood found during the refurbishment of his flat now suggests that he was murdered and his body dumped in the compound. He had recently been to Spain where the knife that killed him was purchased. An animal rights campaigner, sacked security guard and a couple with whom Zac enjoyed extreme sports, are all suspects and all seemed to have been in the zoo the night Zac died. Jack works out the killer's identity even though it means he and the team miss his presentation for bravery as a result.

Now dismissed from UCOS Brian is persuaded by Esther to help her friend Margaret Kirby find her brother Peter Sale, who disappeared six years earlier. In the mean time Brian is bothered by journalist Maxine Wilson, whom he believes has been sent by Embleton to discredit him, and needs Strickland's help to get rid of her. Brian visits Jonathan Epstein, jailed for killing his wife Florence for her money, along with his girlfriend Annabel, who seemingly disappeared with the cash. Sale was Epstein's accountant but Epstein does not know his whereabouts and after the visit Brian is attacked. Accompanied by Esther, Brian sets out to find clues to locate Sale, in the process crossing paths with UCOS, who are investigating a con artist with links to Epstein. Eventually Sale is found and, before parting company with UCOS, Brian discovers that somebody is an impostor and Esther has to save him from being killed by them.

When film critic Oliver Houghton's corpse is found in a sewer Sasha is reluctantly forced to work with Ned as Oliver had been a witness in the unsolved case of gay artist David Straka two decades earlier. Both men were drowned and Danny sees the river Fleet as a link since it featured in David's last project. David's friend Ruth Shireen tells the team that David and Oliver got involved with the occult due to the unpleasant Cyril Watkins though Cyril, now Cecily after gender realignment, explains that there was no harm intended. However a woman playing the part of a sacrificial victim in David's film about the mysteries of the Fleet accidentally died. A trip to the sewers locates her corpse and Sasha beats Ned to finding out her identity and solving both cases.

A blood-stained bust uncovered in a graveyard links to the 2008 murder of alternative health practitioner Jason Henway. Angela Morris blamed him for taking her late mother Gwen off chemotherapy but had an alibi. Jason's business partner Evan Langley stood to gain but points the team towards Jason's brother Douglas, a doctor practising cryopreservation, keeping the clinically dead alive through low temperatures, since he left the business having quarrelled with his brother on his wife's death. As well as solving the murder the team must also deal with Sasha's departure when she is offered an appetizing promotion.