Silent Witness

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.

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.

Forensic evidence given by Nikki contributes to the release on appeal of disturbed ex-soldier David Bennetto, charged with murdering two gay boys, one of whom he had sex with.

The police surround the flat but David hands the gun over to Greg, explaining that it was his father's gun, which he had found and wanted to get rid of.

Following the discovery of a young woman's corpse in a forest Nikki and Jack travel to Scotland to assist DS Jason Ross, who mistrusts local pathologist Dr Jenkins. Prime suspect is hunter and gunsmith Niall Wallace but he is eliminated from enquiries.

Nikki and Jack , joined by the apparently decent Dr Jenkins, unearth more bodies, leading to Niall being rearrested. Steve Boyd reports girlfriend Sarah missing, revealing to Jack what she had told him about her previous ordeal.

Nikki and Jack assist DS Sally Kirchner in identifying teen-aged Alice Preston, who was murdered and her baby taken live from her womb. DNA identifies the father as married Simon Turner, who admits to a one night stand with Alice but claims he never saw her after giving her money for an abortion.

As Nikki tries to explain to Alice's father of her drug involvement Martin Carrisford, the witness to Alice's murder, is also slain. Humadi threatens Nuri to locate the missing drugs though he denies killing Alice. Nuri is shocked to find that Brooke and his wife have Alice's baby .

The body of teenager Katie Bowman is found dumped in an open grave. DI Carter suspects Ryan Kelvin, boyfriend of Lizzie Kennedy, whose daughter Hannah was Katie's best friend. He argued with the deceased girl the day she died and has no alibi.

Things look bad for Ryan when Lizzie tells Carter that he rowed with Hannah a couple of hours before she died as a result of which he makes an unsuccessful suicide bid. Nikki is surprised at the lengths Jack will go to exonerate his brother until he tells her that was the assailant in the criminal case and Ryan took the blame to save his career.