Harry Cunningham investigates when a car accident reveals two bodies inside one coffin. The coffin contained the body of 80-year-old Ethel Mortimer, who was supposed to be there and also that of James Featherton, a high tech sales rep who also had a heavy cocaine habit. Leo Dalton and Nikki Alexander have to deal with the death of a young child who died post-operatively. The pediatric surgeon in the case, Alice Huston, is well known in her field but may be prone to undertaking aggressive surgeries. The pathologists find a connection between the two cases when Featherton's girlfriend is found to be a nurse on Huston's surgical team.

With Claire Kowalski missing and Nikki Alexander unconscious from a blow to the head, Harry and Leo investigate exactly what is going on at the hospital. Harry discovers that a member of Huston's surgical team is not who they claim to be and has actually stolen the identity of someone who died six years before. Blackmail is at the center of it all and it turns out Alice Huston is hiding a secret. However, the killer is identified only by looking to old friendships and the calling in of an old debt.

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.

Things look bad for Ryan when Lizzie tells Carter that he rowed with Hannah a couple of hours before she died as a result of which he makes an unsuccessful suicide bid. Nikki is surprised at the lengths Jack will go to exonerate his brother until he tells her that was the assailant in the criminal case and Ryan took the blame to save his career. Jack pursues Christy, who admits to falling for Katie, unaware that she was a minor but some while afterwards Jack is the victim of a hit and run, which he survives. Ultimately the killer proves to be protecting a professional, rather than a personal, interest though Ryan, cleared of the murders, is not wholly innocent of another crime.