Insurance investigator William Byfield is found gassed in his car after he has sparred with Nikki over a claim for terminally-ill suicide Sally Craven. He was also perturbed about the suspicious death of one Stephen Connelly, which leads to Leo being accused of falsifying the post mortem by William's successor, Clare Ambler. In fact Connelly's details never reached Leo and his widow, bereavement counsellor Rebecca, is not only uncooperative with Clare but is Harry's current girl-friend and overly friendly with coroner's officer David Levin. When it appears that William Byfield was murdered Harry suspects Rebecca of being involved.

Now Leo is under investigation by the police over the discrepancies in Stephen Connelly's file. He think he's found the solution when he notices similarities between the Coroner's file on Connelly and another case he had worked on. Harry is convinced that his new lover Rebecca, Connelly's widow, has nothing to do with the apparent forgeries Leo has found. He believes that the fraud is taking place at the Coroner's office and focuses on David Levin, who had access to the information. After Leo is assaulted outside his home, he is hospitalized and in a coma. On the edge of death, Nikki and Harry learn they may have a major decision to make. When the police find Leo's blood in Rebecca Connelly's home and Levin's body in the boot of her car, they are convinced they have the killer. No one however realizes the true deception that is taking place.

Left wing writer Tom Flannery rings for the emergency services when he finds his investment banker wife Bridget dead at the foot of their stairs, lying in an unnaturally large pool of blood. Both Harry and Detective Superintendant Jenkins find the death suspicious as some blood seems to have been cleaned from the wall, making a 'void', but then Jenkins dislikes Flannery's anti-police strand in his writings and she knows Bridget was insured. Nikki believes the death was an accident until Bridget's sister Muriel tells her that the first Mrs. Flannery also died after falling downstairs.

At the coroner's inquest into Bridget's death Nikki and Harry give conflicting evidence though it turns out that a young policewoman made the 'void' when she slipped on the blood and touched the wall to steady herself. Disturbed mental patient Diamanda Yannis,who had previously attacked Tom's daughter Anna, a nurse, was seen at the Flannery house, covered in blood but she dies after a fight with police. Harry has the first Mrs. Flannery exhumed, proving that someone killed her. Tom admits to Nikki it was him,during a drunken argument over his wish to marry Bridget. He also claims that he killed Bridget but Nikki believes he is shielding somebody else.Is he?

Ruth Gardiner falls to her death from a squat in a high-rise block and Leo - unlike D.I. Neill - realises that she was murdered though Neill seems reluctant to launch a public appeal. Ruth's father tells Leo she left home two years earlier, he assumes to join a cult, but had phoned recently to say she was retuning to him.Reading of the death car salesman Phil tells his girlfriend Danielle that he is an undercover cop working with Ruth - who was staking out a resident in the flats. Danielle meets with Leo, telling him Neill is corrupt and anxious to shut down Phil's operation,which is to expose sex trafficking. Phil - real name Peter Carmody - takes Alex Webb, an apparent suspect,to a caravan where he will be safe. Harry, meanwhile, discovers that a recently deceased family friend had had an affair with his mother.

Carmody goes on the run and Danielle is killed. The same man's DNA is found in her flat as on Ruth's corpse. Leo's partner Janet persuades him that Neill is not dishonest and Neill discovers that Carmody is a car salesman working with Webb. A failed police college entrant some years ago, he has persuaded his wife and mother - as well as Ruth,Danielle and Webb - he is an undercover cop though when Janet interviews his mother she says that he was a fantasist since childhood. Clearly he is a loose cannon, rubbing out those who discover his secret and must be found. Harry discovers that his father was a bully, driving his mother to having an affair.

The team attend at the apparent suicide of student Jason Renfrew at the local university. The Dean tells Leo Jason complained to her about racist bullying and he is found to have swallowed a chip containing photos of the alleged bullies, as well as having a handgun in his locker. Soon afterwards a gunman goes on the rampage, killing several people including the policeman investigating Jason's death. Nikki and Harry are trapped in a classroom with some students, one of whom, the mortally wounded Matt Frisk, was one of Jason's tormentors. Commander Somerville leads the police team who release them though it is Harry who finds the severely injured gunman. However, he fails to spot the bomb planted on campus.

Harry suspects that Scott Weston, the injured gunman, was shot by another person and it becomes obvious that two guns were used in the massacre. Scott's mother tells Dean Mears that Scott and Jason were good friends, Scott looking out for the more fragile Jason. Meanwhile Nikki is held prisoner in the deserted mortuary by unbalanced Neil Corrigan, who appears to have planned the massacre with Jason - who chickened out and killed himself - and then framed Scott. Ultimately video evidence reveals what actually happened, as well as locating the bomb.

The pathologists travel to South Africa, Nikki Alexander's childhood country. Nikki has been there for a short while and with the help of a now imprisoned official from the former regime, they've uncovered the grave of five activists who were eliminated. The problem is that they find a sixth body in the grave. Nikki is also developing feelings for the man who has hired her. Meanwhile, Harry is working with a local pathologist investigating the murder of a young girl. Leo is a bit late in arriving as he was trying to help a young girl who had requested asylum in the UK. He arrives in South Africa only to learn that the young woman has been deported.

Nikki thinks that the sixth body is that of the long missing son of her former nanny, whom she goes to visit. Harry accompanies Sara and her policeman husband as they recover the dead body of Nyasha, killed as an 'example' whilst Daya is returned to the sinister orphanage. Mandisa, the official who took Kudzai there, tells Leo it is a safe haven but it is really a brothel,trading in illegal immigrant girls with no families and the two girls found in the harbour were killed there by brutal patrons and then dumped. Leo leads the police to the brothel and the girls are saved. Nikki, however, faces a far more bitter truth as she realizes Anton has not been honest with her.