Episodes one and two
When a trans man is murdered and a trans activist is kidnapped, the cases are deemed to be linked. But when the DCI releases a suspect prematurely and incriminating evidence comes to light, he tries to blame the Lyell for the oversight. Thomas (Richard Lintern) bears the brunt of the pressure as he volunteers to take the fall – and focuses the team on the search for the perpetrator.
Guest cast members include Andrew Knott, Heather Peace, Johann Myers and Jemima Rooper.
Lift Up Your Hearts
Episodes three and four
After a teenage boy dies in a meth lab explosion, his inspirational head-teacher, Noah Taylor (Colin Salmon), resolves to confront the drug dealers preying on his community. Dangerous batches of new drugs are hitting the streets and its down to Nikki (Emilia Fox), Jack (David Caves), Clarissa (Liz Carr) and Thomas (Richard Lintern) to deal with the consequent rise in overdoses. When tragedy strikes at the heart of the Taylor family, it puts Noah on a collision course with the criminals behind the drugs.
Guest cast members include Samantha Womack, Dan Li, Jo Martin, Hara Jannas and Colin Salmon.
To Brighton, To Brighton
Episodes five and six
A collection of dismembered body parts, covered in intricate Japanese tattoos, have been found in a Brighton waste dump. The team are called in to painstakingly piece them together and they search for clues to lead them to the killer. Outside of the lab, Nikki (Emilia Fox) has some news she desperately wants to share with Matt (Michael Landes).
Guest cast members include Michael Landes, Sebastian Arnesto, Samantha Bond and Fisayo Akinade.
Episodes seven and eight
A car-bomb attack in a quiet suburban street brings back unwelcome memories for Jack, when evidence points to the involvement of a Northern Irish terror group, long thought inactive. As the family of the victim seek their own form of justice, Jack calls an old friend to help them find those responsible and stop the act of revenge from escalating.
Guest cast members include Ian McElhinney, Ray Fearon and Avita Jay.
The Ties That Bind
Episodes nine and ten
Nikki is humiliated in court when a brutal cross-examination suggests she made a grievous error. As she looks back at past cases and battles with self-doubt, Nikki struggles to trust her own instincts when she disagrees with Thomas over a cause of death. When another case is marred by apparent contamination of evidence, the team start to question if the problem lies elsewhere.
Guest cast members include Art Malik, Adelle Leonce, Ingrid Oliver, Kiran Sonia Sawar and Derlva Kirwan.