Harry and the police desperately search for Nikki as they continue to find more bodies. The animal rights activists' target is a well known pharmaceutical firm that is undertaking research on behalf of the government. Leo finally decides on a course of action in testifying at the medical council hearing.

The pathologists investigate when a military helicopter crashes into a refugee detention center. Harry and Nikki actually witnessed the crash and were first on the scene but the case is complex since the center was Ministry of Defense property leased to the Home Office. The team is shocked at the conditions they find in the center and Harry, who has a close friend in the RAF, is shaken when a government Minister attributes the accident to pilot error.

Harry Cunningham investigates when a car accident reveals two bodies inside one coffin. The coffin contained the body of 80-year-old Ethel Mortimer, who was supposed to be there and also that of James Featherton, a high tech sales rep who also had a heavy cocaine habit. Leo Dalton and Nikki Alexander have to deal with the death of a young child who died post-operatively. The pediatric surgeon in the case, Alice Huston, is well known in her field but may be prone to undertaking aggressive surgeries. The pathologists find a connection between the two cases when Featherton's girlfriend is found to be a nurse on Huston's surgical team.

Following a court appearance for drunk driving, Leo is required to perform unpaid work as a punishment, assisting AJ, a community worker on a run-down,largely black-occupied housing estate in South London. AJ is hoping to divert boys away from crime by encouraging them to do sports, and, though initially dismissive of Leo as a white intruder, comes to respect him after he has saved the life of Errol, a former gang member now anxious to keep his little brother Levi out of trouble. Errol has been stabbed in the leg by members of a gang from a rival estate and Leo stops him from bleeding to death. Earlier in the week a young girl called Shana Block was stabbed to death at a funfair and her murder recorded on a mobile phone. As Shana lived on the estate police sergeant Wallace involves Leo as a go-between with the suspicious residents. Also on the scene are Harry and Nikki, the latter dating Ryan, a young Scottish paramedic she met when called to the scene of Shana's death. Before any arrests can be made, Richard Ojana, a member of a rival gang, is shot in broad daylight and nobody is willing to come forward as a witness. Believing he knows who the killers are, Errol goes off into the night, but the next day his corpse, tarred and feathered, is dumped on A.J.'s recreation ground.

The team is called in after Mr. Stickley of the Police complaints Board feels that something is not right about an armed police raid on a house where several people were killed, including one of the officers and a mystery woman. A young Muslim called Melik has been badly wounded and lies in hospital. Mr. Stickley believes the policeman was killed by Rhys Allen, a colleague who was having an affair with the deceased's wife. Melik's sister Isra confides in Nikki that all the 'suspects' were unarmed and not terrorists and fears of a cover-up by the authorities are not helped by the aggressive attitude of Inspector Transfield, particularly when Nikki is attacked and evidence stolen from her laptop.

A severely mutilated corpse is found on a railway line, belonging to a known paedophile in his twenties, Francis Neil. Noel Hopkins is arrested, following revelations years earlier of an affair with a young pupil Nikki believes to be Francis but he is released due to insufficient evidence, though he is sacked from his job and his house torched, his saviour being Danny, father of the dead boy Michael. It is ultimately revealed that in fact Liam did not exist - he was the 20-something Francis, obsessed with Michael, and both were victims of the paedophile ring. Ultimately Nikki helps Noel to overcome prejudice and regain his job.

Whilst cage-fighting Jack takes on young Dean Fallon, drug dealer and son of career criminal Terry Fallon. When policeman Sam Honeywell's corpse is discovered in his burnt out car Dean is the main suspect after Honeywell had arrested him but is released for lack of evidence. Sam's colleague Carl Parry is then arrested when it is made known that Carl's wife Kate was having an affair with the dead man. After Dean has fallen out with his friend Jason Simons over Dean's girlfriend Tess Hughes Tess finds drugs hidden in her father Stan's garage, which she takes to Jason. Soon afterwards he too is killed.

Examining Kevin's corpse Nikki is puzzled by stun marks on the body and the fact that Jackie had set up a camera in his room. Thomas is also curious regarding two other mysterious deaths, one at Kingscote Bows, the other at the Pleasant Manor care home, where both were regularly visited by Dr Kahari. When Serena goes missing and Tilly is found dead after threatening to expose Flannery Clarissa books herself into Pleasant Manor to investigate herself,. She unmasks the killers but needs to be rescued by Jack when she puts herself I danger.

When a skeleton is found buried in cement, the team have to work out how and why he was found there. Meanwhile, Clarissa receives some devastating new about her mother.