Silent Witness Series 20 (2017)

When a people smuggler is found dead in the City, Nikki must delve into London's illegal immigrant community. She meets a vulnerable Syrian teen called Akka who is in need of help, putting Nikki in a moral dilemma - and the killer is still on the loose.

When Nikki, Jack and Thomas make a horrific discovery in the van, they are confronted with the work of a killer who preys on illegal immigrants. With the help of Clarissa, they must work out where the killer will strike next before more vulnerable people meet the same fate.

When a photogenic young schoolteacher goes missing, Jack and Nikki are called to the scene and quickly find themselves at the centre of a media storm. Meanwhile, Thomas fights a lone crusade for justice for a troubled young woman who was killed in puzzling circumstances.

Having found a link between the two cases, the team struggles to make sense of it. Nikki visits a disgraced former colleague who may hold the key. Thomas uncovers the bizarre truth about how Tina died.

A woman's body found floating in the Thames leads Nikki and Jack to a community on the banks of the River Lee. Three years ago a teenager called Ruth Tresize went missing from the area, leaving the locals haunted by suspicion and grief. A fresh spate of killings reopens these old wounds.

Nikki is under fire for leaking information on a suspect, and Thomas is called in to play peacemaker. Jack and DI Ashton track down the mystery witness. Before the killer strikes again, the team must uncover the true story of Ruth Tresize's disappearance three years earlier.

When an East End father and son are killed in a shocking road accident, Nikki and Jack find themselves working alongside a police officer with a vendetta. Clarissa summons her husband Max, a digital forensics expert, to help crack the case - and uncovers disturbing video evidence.

Nikki helps Becky come to terms with her trauma. Jack is paranoid that Clarissa will leave the Lyell Centre. Paul is in way over his head.

Nikki travels to Mexico when her friend is killed in a carjacking, but she soon makes a discovery that sets her on a collision course with some dangerous and unpredictable forces. Thomas sends Jack to bring Nikki back, but soon he is knee-deep in the unfolding situation.

With Nikki locked in a struggle for survival, Jack must use all of his abilities to track her down. When a mysterious person calls to make demands in return for Nikki's release, Jack's moral principles are put to the test. And with life and death in the balance, every decision counts.