Top-flight footballer Isaac Dreyfus' days at the top are numbered when a sex tape links him to the brutal murder of a young woman, threatening to destroy his reputation and marriage. Nikki struggles to come to terms with Leo's death following the arrival of the new Lyell Centre boss, pathologist Thomas Chamberlain. However, her feelings surface when DI John Leighton and DS Anne Burchett demand results in two unsolved cases - a mother and son murdered in their wealthy London home and the disfigured body of a young woman.

Nikki delivers ground-breaking testimony in the high-profile appeal court case of David Bennetto, a convicted killer who has spent the last six years behind bars for the murder of two gay teenagers. But bitter DI Rachel Klein remains unconvinced that she caused a miscarriage of justice and cannot hide her contempt, especially when another young man is found dead bearing the same hallmarks of the previous murders. Meanwhile, Nikki's professionalism is brought into question due to her increasingly close relationship with lawyer Greg Walker.