Silent Witness

A private jet crashes into woodland outside London. Its passengers include the former US Ambassador, Jonathan Kraft. Nikki calls her partner Matt from the crash scene to break the news: his friend, and former colleague did not survive the accident. Matt is desperate for answers. When Thomas is called to an apparent suicide of a successful businessman, he finds unexpected connections to the plane crash. Are they dealing with a coordinated attack?

Nikki and the Lyell team continue to investigate the plane crash, ruling out an explosion and engine failure. Suspicion turns to Rowan Cole, the so-called Deadhead - a non-flying pilot who was hitching a lift back when his intended flight was cancelled. The investigation takes a turn when they discover a connection to a sinister online forum. Nikki's partner Matt is grieving following the death of his close friend, putting their relationship under strain.

When a body is found in a field near the village of Hartford, Nikki and the Lyell team confirm it is that of missing teenager Jason Forbes. Working to the theory that most killers strike close to home, the ambitious DCI Claire Ashby is committed to proving the guilt of her main suspect, local locksmith Malcolm Wilde.

Investigating the murder of a teenage boy, Nikki and her team are forced to question police methods. Although Thomas discovers evidence that throws the time of death into doubt, DCI Claire Ashby seems more concerned with building the case against her main suspect. With pressure building on the police to secure a conviction, the Lyell team must fight to ensure that inconvenient truths aren't overlooked. Meanwhile, Clarissa notes a troubling parallel with a case from the start of her career. Is the real murderer still out there?

The body of a woman is found on railway tracks in London, badly damaged from electrical burns. On the mortuary slab, the woman's recent and historic injuries suggest years of abuse, likely within the home. It's a difficult post-mortem for Nikki, as she is troubled by memories from her childhood.

Nikki determines that Jenny must have died before making contact with the tracks. But when the search for Jenny's killer hits a wall, her friends at the women's refuge seek answers. Meanwhile, Thomas' political ambitions lead him to make friends in high places. Offers are made to open all the right doors for Thomas, but what do they want in return?

Teenagers messing around in a stolen car collide with a concrete pillar in a multistorey car park. The joyriders escape, but within the smashed concrete, the unmistakable form of a skull is revealed. After painstakingly extracting the skeleton encased inside, Nikki and the Lyell team must investigate a suspicious dating back 20 years. Meanwhile, Clarissa faces a difficult decision regarding her mother's care.

The Lyell team identify the concrete-encased remains as those of Derek Marshall, survived by his wife Sue and sister Ann. Clarissa traces payments to a cryogenics facility, leading to the discovery of another suspicious death. Lacking any proper documentation, the coroner orders a post-mortem into the cryogenically frozen body. How did they die, and why was the decision made to freeze them?

Thomas investigates the case of John Sealy, a soldier who died during a military training exercise involving exposure to CS gas. It appears John died from an aneurism, but when Thomas discovers the trace of a possible nerve agent in his system, the family are desperate for answers. Was a chemical weapon involved or is there a more innocent explanation?

Jack is rushed to hospital after collapsing at the scene of a car crash. Following Thomas's discovery that soldier John Sealy may have been exposed to a nerve agent, is it possible someone is targeting the victim's family? With Jack's life in the balance, it's down to Nikki, Thomas and Clarissa to find the truth and save their friend.