Nikki visits the only key eyewitness, Isra, the teenage sister of one of the suspects who insists her brother is innocent. Nikki is appalled by the harshness of her treatment, and the team begin to seriously suspect that the truth is being covered up. Meanwhile, Rhys is on the run, and Harry is shocked when he discovers the identity of the unknown victim.

Harry and Nikki discover more about the tangled lives of the inhabitants on Magnolia Drive.

Harry puts his professional career on the line to prove his lover's innocence after Leo is attacked and Levin turns up dead, but Nikki is concerned that Harry's emotions are clouding his professional judgement.

Nikki suffers amnesia after being attacked in the hospital basement, so it is down to Harry to work out why she was there. It soon transpires that there were two operations on the child that died, the second to deal with complications following the first.

When the badly decomposed body of a Hasidic man is discovered on disused wasteland, Harry is tasked to investigate his death, and to treat the community with care. Everything points towards a brutal anti-Semitic murder by a Polish laborer - but when the time of death contradicts his wife's last sighting, Harry becomes suspicious. Leo, meanwhile, is trying to unravel the events leading to the death of an Australian backpacker at a party.

While Harry and Nicky investigate DI Bridges, Leo puts himself in danger when he follows his instinct and trails violent prison officer Kessler.

Whilst Nikki, Leo and Jack struggle to ascertain how Deanna was killed and ended up in the Thames, DI Gold focuses on two main suspects in John Briggs' inner circle. However, when Geraldine makes a sinister confession about why she gave her daughter up for adoption and disowned her wealthy family, it dramatically changes the course of the investigation.

When Rachel Harrington's bones are found in Zambia, her expat father and local mining engineer, Stephen, asks the team to come out to investigate. Rachel had been accusing the government of a health cover-up, and an initial examination shows evidence of multiple stab wounds. But as the team investigates further, it seems the government weren't the only ones to have been rubbed up the wrong way by Rachel.

Harry and Nikki's tentative new relationship is jeopardized when Harry's ex-girlfriend is killed. Nikki takes on the case, which looks like suicide, but Harry becomes obsessed. Meanwhile, Leo works on the elaborately staged murder of conceptual artist Jimmy Triangle.

A paranoid schizophrenic goes on a violent frenzy in a busy high street and two people are left dead. Then when a young man from the same care home commits suicide, Nikki becomes convinced that there is a connection. Meanwhile Harry tries to find the truth about a teenage suicide's death for her devastated mother, and Leo investigates the murder of a bank manager.