Fresh from her successful SWAT raid on a group of Russian gangsters DCI Sasha Miller arrives at UCOS to replace Sandra. She is friendly and informal but initially fails to win over Gerry, who misses Sandra. Her first case involves the twenty-five year old murder of Italian Allesandro Manzini, reopened when a knife is found at the allotment he once tended. Massimo, whose son married Allesandro's daughter Giulietta, tells the team that there was anti- Italian feeling on the allotment, especially from two World War Two veterans, whilst lorry driver and druid Ray Barlow is also suspect, having disappeared after the murder. This suspicion is heightened when Giulietta and Ray admit to an affair but Dan's research into wartime Italy changes everything, leading to a confession. Sasha's private life, however, does not run so successfully.

Gerry is approached by Ralph Paxton, a boyhood friend who became a career criminal and was imprisoned for a jewel robbery. Ralph believes that his grandson, architecture student Jake was murdered by his partner in crime Wayne Pelham because the boy discovered the loot hidden in a tower block due for demolition. After interviewing Jake's brother and his college tutor the team locate Pelham, who informs them that others knew about the hidden jewels. The team eventually end up with two prime suspects, both of whom believing that they were acting out of principle, though one is the killer. Gerry also has to overcome his dislike of the solicitor to whom his daughter Caitlin is getting married.

Thirty years after the death of a suspected terrorist, the man's daughter receives an anonymous note claiming he was murdered. Clues lead the team to the Greenham Common antinuclear protests of the 1980s.

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.