Silent Witness is back with its 22nd series on BBC One tonight but who's the cast and what's going on this time around?
BBC's Silent Witness continues its new 10-part run from 9PM this evening.
The longest running British crime drama currently airing on TV, the series follows a team of forensic pathologists helping police solve murders using clues found on the bodies of the victims - the silent witnesses.
Emilia Fox, Richard Lintern, David Caves and Liz Carr return as the dynamic Lyell unit, for five new topical thrilling two-part contemporary stories set against the familiar landscapes of London.
Silent Witness spoilers
This week's fourth and final two-part episode is called Betrayal.
In episode one on Monday night, Nikki (Emilia Fox) is humiliated in court, when a barrister accuses her of making a serious error in the case of a policeman who may or may not have been murdered. Meanwhile the team investigate the death of a medical researcher, found in a canal, with mysterious puncture marks on his body.
In the second part airing on Tuesday, When Thomas (Richard Lintern) sides against her findings on a controversial case, Nikki suspects foul play and takes steps to prove her theory. Meanwhile Jack (David Caves) and Clarissa (Liz Carr) follow a forensic trail connecting the dead researcher with a billionaire scientist and a secret testing program.
Emilia Fox, David Caves, Richard Lintern and Liz Carr play Dr Nikki Alexander, Jack Hodgson, Professor Thomas Chamberlain and Clarissa Mullery. They are joined by Art Malik, Adelle Leonce, Ingrid Oliver, Kiran Sonia Sawar and Dervla Kirwan.
You can watch episodes for free online and catch up (for UK viewers) via the BBC iPlayer here.
Silent Witness airs tonight, Monday 4 February on BBC One from 9PM and continues Tuesday, February 5.