After insurance investigator William Byfield is found dead, Harry's initial examination makes it look like it could of been suicide. After another examination, the team start to believe that he could have died from cyanide poisoning. Hos replacement, Clare Ambler begins to believe that his death could be linked to his investigation into the death of Stephen Connelly.
Leo thinks might have worked out why he has no memory of Connelly's post-mortem but before he can prove he is innocent he is hit in front of his house and ends up in a coma. Coroner David Levin is discovered dead and it is revealed that he has also been poisoned by cyanide. With Rebecca looks like she could have committed the murders Harry refuses to believe she is responsible and he ends up putting his career on the line. Harry is able to find evidence that Levin committed suicide and when he goes to talk to Rebecca all he finds is nobody at her house.
Harry and Nikki are on different sides following the suspicious death of banker Bridget Flannery. Her husband Tom, is the main suspect and he insists that she fell down the stairs. Harry conducts the post-mortem for the police investigation whilst Nikki is asked to do one by Tom's solicitor. They both come up with different conclusion about how she died. When Nikki's learns that Tom's first wife, Olga, died in similar circumstances she begins to doubt Tom's innocence.
As the case into Bridget's death continues, Harry and Nikki find themselves falling out. Tom is arrested after pictures of his first wife's death are leaked. Harry decides to try and find out more about Olga's death. Nikki is determined to find out exactly what happened on the night Bridget died which leads to more tragedy for the Flannery family.
Leo returns to work after recovering from his injuries. He finds himself working on the case of a shattered body of a young woman, Ruth Gardiner, who is thought to have fallen off the roof of a block of flats. Leo discovers that the girl was shot in the head before being thrown off the roof and the investigation into her death is reopened. Leo begins to wonder if there is a cover up going on when it looks like the girl could of been one of Phil's informants and DI Neill is reluctant to pursue that line. Neill finds the investigation leading him to Alex Webb after a gun is found.
A large amount of blood is found in a flat that has been rented in Danielle's name after the police are called there. The DNA found there matches that of Danielle, Alex and Terry, who was Ruth's lover. Leo is convinced that Phil is involved in the hug but he still lacks any evidence to prove his theory. It is later revealed that Phil has been leading a double life and that is also Terry. The search for Phil leads the police to some secluded woods where Danielle's body is discovered. Following Leo's examinations Peter is arrest.
Leo liaises with the Dean and investigating officer DC Saich after a suicide at a local university. They soon find out that Jason was being bullied before his death. After a gun and live ammunition are found in Jason's locker alarms bells ring. The remains of a memory card are found in his stomach which reveals pictures of students, some of whom were his alleged bullies. Harry and Nikki find themselves trapped in one of the campus buildings when shots are fired. After firearms officers manage to make their way into the building suspected shooter Scott Weston, is found with a bullet in his head.
Harry stays to help the paramedic who is looking after Weston as the injured are helped out of the building. Nikki returns to the Lyell Centre where she ends up not being alone. A student called Neil locks the door after entering the lab. Leo discovers two guns where used in the shoot out after he starts to carry out some post mortems on the dead. Nikki discovers more as Neil points a gun at her.
After she is hired as a consultant forensic anthropologist by a private investigations firm, Nikki finds herself returning to Cape Town where she grew up. Nikki becomes involved with Anton and they investigate after the remains of five young men who disappeared in the mid-Eighties are discovered. Nikki is due to be joined in Cape Town by Harry and Leo who are to take part in a forensic pathology international conference. Harry ends up working with Sarah after the dead body of a young black woman is discovered. Leo's departure to Cape Town is delayed by an asylum case back home and when he arrives in Capetown finally he finds the person involved in the case he was working on has now been deported to Cape Town. Leo is determined to help her but before he can she vanishes. Anton and Nikki discover their are six skeletons instead of five.
Two more girls' bodies are examined by Harry and Sarah and they find the same drug in their systems as previously found in the body at Hout Bay. Nikki is unable to work out who the sixth skeleton belongs to. Leo is worried after he receives a call from Kudzai. After meeting with Harry, Leo finds out that she has been sent to the same place as the three dead girls are linked to. Nikki finds out from Captain Brackenhall that Anton's business partner was involved with the Kensington Five hug leaving her with some difficult decisions to make.