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.

In 2010 trainee doctor Lydia Dryden was found dead in her flat after visiting Bar 393 night club. Neighbours reported a possible stalker lurking outside the building but her parents, both surgeons, do not recognize him from the Identikit picture. Married Laurence Devlin, another surgeon, denies having an affair with Lydia though it transpires that he is her actual father, which her mother Monica has kept from husband Hugh. Lydia's sister had a drug habit and Lydia was suspected of stealing from the hospital medicine cabinets to help her. then the stalker is revealed, a man whose wife died during an operation performed by Laurence and Lydia. He denies killing her but helps lead the team to the true murderer.

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.

Elderly dementia sufferer Nancy leaves her care home to report that her policeman husband Jimmy, who disappeared in 1956 was actually murdered. Harry Page, an old friend of the couple, reports that Jimmy had gambling debts and got into a fight the night that he died. Sasha takes Nancy back to her old house where she recalls Jimmy's violence and jealousy. A grim secret is discovered in the bedroom wall, in turn leading to the solution of the murder. Meanwhile Steve is called to the police station when his son Stewie is cautioned for minor drug possession, which brings him into conflict with his ex-wife Tricia. They do not part on good terms.

Cuando se encuentra el cadáver del crítico de cine Oliver Houghton en una alcantarilla, Sasha se ve obligada a trabajar a regañadientes con Ned, ya que Oliver había sido testigo en el caso sin resolver del artista gay David Straka dos décadas antes. Ambos hombres se ahogaron y Danny ve el río Fleet como un vínculo, ya que apareció en el último proyecto de David. Ruth Shireen, amiga de David, le dice al equipo que David y Oliver se involucraron en lo oculto debido al desagradable Cyril Watkins, aunque Cyril, ahora Cecily después de un cambio de género, explica que no se pretendía hacer daño. Sin embargo, una mujer que interpretaba el papel de víctima sacrificial en la película de David sobre los misterios del Fleet murió accidentalmente. Un viaje a las alcantarillas localiza su cadáver y Sasha supera a Ned al descubrir su identidad y resolver ambos casos.

In 2008 body-builder Mark Rix died of a heart attack, seemingly caused by a surfeit of steroids. Now a sword is found in his old lock-up, which decapitated an unknown man just before Mark died. Mark was a member of Imperium, a group re-enacting life in Ancient Rome and Steve and Sasha learn from Imperium members Julia Kane and Tim and Tessa Dugdale that he believed himself to be Marcus Rex, incarnation of a gladiator. Forensic scientist Fiona Kennedy identifies the murder victim as a Romanian gangster who sold illegal steroids and the team deduces that Rix used Imperium's foreign dates to import them. After confessing to Fiona that his estranged wife Sarah is in a secure unit, having tried to kill him and his daughter, Danny goes undercover at Imperium, where he recognizes Julia as another undercover cop. Eventually the team learns the truth about both men's deaths from Julia before Danny goes on a date with Fiona.

Illegal Turkish immigrant Asye Ersoy was working as a barmaid in 2010 but disappeared following a fire which killed the pub's landlord Richard Gibson. Now she has been traced but denies committing any crime. The pub's former pianist Jason claims that Richard was happily married to wife Joanne and she endorses this. Relations with his brother Gavin, a slot machine vendor who wanted to buy the ailing pub, were less harmonious whilst Joanne believes Richard was having an affair with Asye but did nothing about it. The identity of Asye's actual lover and a scam involving the sale of cheap wine, dressed up to appear as of better vintage, are both uncovered before the real killer is unmasked though Gerry and Steve regard the case as a welcome diversion from Sasha's attempts to enter them in a five a side contest.

El equipo se da cuenta de que el ADN del vendedor adolescente del mercado, Spencer Rogers, arrestado por lanzar un ladrillo en la autopista, coincide con el de Agnes Bradley, intérprete y miembro del club de ajedrez, quien fue asesinada en 2010. Cuando la madre de Spencer, Kelli, le dice a Sasha que Spencer fue el resultado de una violación por parte de un hombre desconocido, queda claro que el violador es el asesino. Los sospechosos incluyen a Jeremy Powell, quien, según el capitán del club de ajedrez Viktor Proust, se enojó porque nunca pudo vencer a Agnes, y al diplomático chileno Carlos Álvarez, quien puso a Agnes en una lista negra después de que una de sus traducciones advirtiera a los estudiantes sobre su mujeriego. Mientras el resto del equipo está ocupado tratando de atrapar al asesino, Steve está ocupado llevando a su padre moribundo, Robbie, lleno de odio, a un hospicio en Londres.

Después de que un aficionado detective es asesinado, se encuentra una foto de Danny en la escena. Resulta que Danny era su amigo, y él promete encontrar al asesino. Las pistas llevan a un asesinato de hace 25 años y a un viaje al campo.

Más de treinta años después de la muerte de Amy Taskerland, una escolar, en un baile de fin de curso, se descubre una cápsula del tiempo que contiene una cinta donde expresa su miedo hacia Alec. Ni su padre William ni su mejor amiga Harriet pueden identificar a Alec, aunque el director de Amy queda bajo sospecha ya que tenía una aventura con ella mientras salía con la maestra Carla O'Brien. Luego, Danny descubre que Amy parecía estar recitando un discurso para ser utilizado por la reina en caso de guerra nuclear, lo que lleva a descubrir la identidad de Alec y, a su vez, a descubrir quién mató a Amy. Mientras tanto, Gerry tiene una sorpresa en la despedida de soltero de su futuro yerno, mientras que Strickland prepara una sorpresa aún más grande y Danny logra hacer de Cupido exitosamente para Sasha.