The body of teenager Katie Bowman is found dumped in an open grave. DI Carter suspects Ryan Kelvin, boyfriend of Lizzie Kennedy, whose daughter Hannah was Katie's best friend. He argued with the deceased girl the day she died and has no alibi. Ryan is also Jack's half-brother, whom he has not seen since he was forced to testify against him in a court case some years earlier. To avoid a clash of interests Thomas brings in pathologist Helen Ferguson, suspending Jack. Jack however does his own sleuthing. showing Carter that Katie had been to a club where she met Christy Nash, a married doctor with whom she had sex. Nash's wife gives him a false alibi to protect their daughter but declares her intention to divorce him. Ryan is bailed and moves in with Jack, who now doubts his brother's innocence whilst Hannah is killed after confronting Dr Nash.