When three bodies surface in the garden of a rented house in North London, forensics discover prints which link back to an unsolved crime that no one in the Metropolitan Police wants to remember. The prime suspect of the first case was an officer from the force, but since no conclusive evidence was ever found, the police closed ranks to prevent the media frenzy that would surely follow his discovery. Now, as the past case begins to link unavoidably with the present, DC Ebony Willis is sent to see if she can uncover the whole truth about their suspect - Carmichael.