Silent Witness

An insurance investigator is found dead, apparently suffocated from the exhaust fumes piped into his parked car. Initial examination suggests it was a likely suicide, but when a technician later passes out while handling the stomach contents, the team suspect the man may have died from cyanide poisoning. This raises the possibility of murder and the suspicion that it could be linked to another untimely death.

As another cyanide-poisoned body is found and Leo is left fighting for his life after being attacked, a complex web of deceit begins to emerge. Harry becomes romantically involved with the main suspect, leading Nikki to question his professional judgement and relationships become strained.

Harry and Nikki find themselves on opposite sides of a high profile case involving the suspicious death of wealthy banker Bridget Flannery in her Hampstead home. Suspicion quickly falls on her husband, media personality Tom Flannery and while Harry conducts the official post mortem for the police investigation, Nikki is hired to do a second one by Flannery's solicitor. They arrive at very different conclusions and soon fall out, but a revelation begins to challenge Nikki's belief.

At the Coroner's inquest, Harry presents the investigation's post mortem report and concludes that the injuries suffered by Bridget Flannery could only have been caused by blows to the head with a sharp object. Nikki argues that a cocktail of alcohol and prescribed drugs led to a fall, which caused the injuries from which she died. Press stories relating to the death of Tom Flannery's former girlfriend stir up emotions, but Nikki is determined to look beyond the police's blinkered investigation.

Leo returns to work after his recovery from a life-threatening head trauma. His first big case involves a young woman, Ruth Gardiner, who apparently jumped off the roof of a derelict tower block. He soon begins to notice that it may not be a suicide. The investigation reveals that the dead girl may have been an informant for an undercover cop, leading Leo wondering if there is a cover-up underway. He is contacted by Danielle, the girlfriend of a rogue undercover detective, whose life is in danger and the situation begins to escalate.

Leo begins to suspect a number of names are connected Ruth's murder and when the police are called out to a flat, rented in Danielle's name, they find blood everywhere. His investigations lead to an unexpected twist in the tale.

Consecutive student suicides on the university campus where the Lyell Centre is situated lead Harry and Nikki to discover a gun and live ammunition are discovered in the dead boy's locker. They are soon caught up in a horrific campus shooting. As they tend to the victims, Leo watches on helplessly as CO19 storm the building.

As Leo conducts the preliminary post mortems on the victims, it becomes clear that 2 guns were used and that the suspect may not have carried out the shootings. Another student holds Nikki hostage in the Lyell Centre, leading to a shocking discover and the realization that the shooter had a much bigger agenda.

Nikki returns to her childhood home of Cape Town when she is hired as a consultant by a private investigations firm to assist in the search for the remains of five young men who disappeared in the mid eighties. Harry and Leo are due to join Nikki in to take part in an international. When Harry arrives, he's whisked away by Nikki's former mentor, Sarah, and is drawn into her work investigating the death of a young black woman. Meanwhile, Leo has been delayed by an asylum case back in the UK. Upon his arrival he receives a call about the case and uses his expertise to help the young girl in question.

Harry and Sarah examine two more girls' bodies and discover in each traces of the same suspicious drug found in the first girl. Leo is relieved to hear from Kudzai who assures him that she is safe, but Leo is unsettled by the call. When he meets up with Harry, Leo's concerns are confirmed as he realizes that their two investigations are linked. Meanwhile, Nikki manages to prove that five skeletons are indeed the remains of the Kensington Five, but she still cannot identify a sixth. Her work on identifying the sixth body takes on personal importance.