Harry discovers evidence of extensive plastic surgery on the corpse of the bodyguard as an autopsy is carried out. Nikki takes a look at the evidence from the 1996 disappearance of Jacob. The Van Burens' version of what happens becomes increasingly unlikely and when the body of the family's au pair, Mary Olivant, is found hanged near the Van Buren family home, Leo discovers the remains of a young boy in the ground.

Chief Inspector Rebecca Woods and some members of the Diplomatic Protection Group head to the Dutch embassy to investigate a shooting. They discover Ambassador, Pieter Van Buren, holding his wounded daughter Klara. He demands that the the DPG team leave and Woods has no choice but to agree given it is officially Dutch territory.

Nikki makes her way to Budapest but there's not much she or Leo can do as every move they make is being watched by Tibor Orban. Leo manages to secretly meet Nikki where he reveals that Harry is still alive. Harry explains why he had to fake his own death and continues that he must find out why Anna was killed and unravel the dark secret of the prostitution racket.

Harry is reunited with Anna Sandor when she calls him to Budapest to perform a second post-mortem on the body of a drowned prostitute, Sofi Mustafova. As they get reacquainted, Anna tells him she believes the death is suspicious and may be linked to her own investigations into the disappearance of other pregnant prostitutes.

An X-ray of Lt Lockford's skull reveals a second bullet, confirming suspicions that he was murdered. Danny Ferris's father is not satisfied with the verdict on his son's death, and asks Nikki to perform a second post-mortem, and as the investigation continues to unravel, a tragic secret is revealed at Hillsdon Army Base.

Nikki is called to perform a post mortem on the body of a woman found in a river, and the discovery that she had recently given birth causes the pathologist to worry her child may be abandoned somewhere. Meanwhile, Harry investigates the apparent suicide of a lieutenant at a nearby Army base, and suspicions soon arise that the two cases may be linked.

After a preserved female body is discovered buried in a peat moor in Sheffield, DI Sonia Hardwick turns to an archaeologist called Professor Patrick Cain for help. Nikki discovers knife wounds to the hands which the professor believes may indicate a ritual killing as the autopsy on the body is carried out. Leo ends up searching through his archives for a case he dealt with in Sheffield in 1985 that were committed by self-confessed serial killer Karl Bentley. As he examines the body himself he is caught by Nikki and Leo tells him he thinks the body could belong to a woman called Jodie Fisher who went missing at the time.

Leo finds himself haunted by past memories when he returns to Sheffield after an ancient body is unearthed on Bleaklow Moor.

Nikki's mental instability worsens, and Harry and Leo are forced to get her psychiatric help. When the true identity of the murderer is discovered, it becomes a race against time to save Nikki's life.

When the pathologists investigate three suspicious deaths in one night on the same ward, it looks like hospital staff may be behind their murders. Nikki becomes increasingly disturbed by a rape and murder case involving a young child.