Premiership footballer Isaac Dreyfus finds his career in tatters after a sex tape links him to the brutal murder of a young woman, threatening to destroy both his reputation and marriage. He is desperate to prove his innocence, while Adam Freedman turns to a mysterious source for help to avenge the murder of his wife and child. Nikki finds it hard to deal with Leo’s death following the arrival of the new Lyell Centre boss, pathologist Thomas Chamberlain.

Isaac Dreyfus fights to prove his innocence, whilst Adam Freedman turns to a mysterious source for help get revenge for the murder of his wife and child. Nikki questions the motive behind the murders and a re-examination of the Freedman crime scene leads Jack to make a shocking discovery.

Nikki finds her professionalism being brought into question during the case of convicted killer David Bennetto, who was jailed for the murder of two gay teenagers. Thomas attempts to save The Lyell Centre’s reputation.

Thomas is under increased pressure from DI Rachel Klein and the Home Office as he battles to save the Lyell Centre's reputation. Peter Masham makes an unlikely deal with Bennetto's brother-in-law. Jack and Clarissa finally uncover the true identity of murder victim Byron Lee.

Nikki and Jack head to Scotland to help earnest rural detective DS Jason Ross investigate the chilling murder of a lap dancer found in a remote forest. In their search to find a suspect, the team clash with rogue city detectives DS Mike MacNeil and DI Simon Laing. But as more human remains are unearthed in the forest, it becomes horrifyingly apparent that a dangerous serial killer is at large. News of the murders unsettles new mother Sarah, who is harbouring a dark secret from her partner Steve.

Nikki, Jack and DS Ross are feeling the pressure to close the net on a serial killer abducting young women. Concerns increase about missing Sarah, and solving her mysterious disappearance becomes an urgent priority for the team.

After the body of a pregnant Northern Irish girl is found, Nikki and Jack need to locate the baby that has been snatched from her womb. Thomas discovers the girl’s connections to a criminal underworld.

Martin is found dead in suspicious circumstances. Nuri becomes increasingly desperate to locate the missing drugs, with some tragic consequences. Nikki attempts to help a grieving William come to terms with his daughter Alice's death and his missing baby granddaughter.

Jack becomes involved in an investigation into the murder of a 15-year-old girl owing to his personal connection with the prime suspect. Thomas needs to clear up the conflict of interest.