As Leo's replacement Thomas Chamberlain arrives Nikki investigates the murders of Rachel Freedman, shot in the head, and her little autistic son Nathan, who was poisoned. Nikki rejects policewoman Anne Burchett's theory that Rachel killed them both but is perturbed when an impostor, claiming to be Rachel's sister, visits the morgue. At the same time the disfigured corpse of Eva Liron is discovered, killed with the same poison as Nathan. She had been the nanny to French hot shot footballer Isaac Dreyfus and was planning to blackmail him over a sex tape of them both. Jewish Isaac is a controversial figure due to his anti-Muslim sentiments but he denies ant part in the murders. Then another victim, Isaac's agent Mousa, is discovered dead.

Isaac is arrested but club bosses deny knowledge of the sex tape whilst Rachel's widower Adam tells the police that Eva Liron had been Nathan's nanny but had left suddenly. With Mousa shot by the same gun as Rachel ambitious Inspector Leighton assumes that he was delivering the blackmail hush money and was killed by Isaac, whom he wants to nail, though the pathologists will not assist in any stitch-up. Then Clarissa discovers that Adam and Isaac both donated money to Israel and the motive appears to be that they were targeted by anti-Zionist terrorists after Eva had picked them out. But who is the mystery woman posing as Rachel's sister and who perpetrated the murders? The pathologists assist the police in finding out.

After US ambassador Jonathan Kraft has given a television interview his aide Ryan Reed is shot dead. The embassy's deputy chief Matt Garcia discovers the married Reed had been having an affair with colleague Terry Lefoe but she has an alibi and terrorism is suspected when Matt receives a parcel bomb which is intercepted. Then Helen Vine, a respected American pathologist who, like Ryan,, had spent time in Africa, is also murdered. Confused psychiatric patient Fergus Weir is released to the care of his sister Ella but disappears and CCTV shows him to have been at Helen's hotel, leading to his arrest and confession. Nikki spends the night with Matt but has a rude awakening.

Matt is found alive after his abduction but admits that the kidnapper wanted information about an incident that happened in Africa when Helen and Ryan were there. All of the victims, including another in Florida, were murdered in the style of assassinated American presidents but Fergus has an alibi for them all though Matt learns that he has information which identify the murderer. Now the police and the pathologists must work together before Fergus is also killed.