The mystery of the severed arm is partly solved when the police discover a body floating in the river with a missing arm. The pathologists continue their investigation with little help from the police and DCI Deacon in particular. When she reveals to Tom that two of the men in the accident were undercover policemen, he realizes that Sam was correct and that he is being manipulated. The police refuse to tell them what is going on and Sam's interference has serious consequences. Harry continues to try and find a balance between detachment and compassion as one of the survivors of the crash seeks his assistance.