Dead Letter

Detective Chief Inspector Bill Green of Scotland Yard receives an anonymous letter from a former army comrade who has inadvertently witnessed a murder. The reason has good reason to maintain anonymnity because one of the accomplices happens to be a local policeman. Green and his partner, Detective Chief Superintendent George Masters, face one of the greatest challenges of their careers as they launch a sublte investigation without arousing the suspicion of a corrupt colleague who is dangerously adept in using his professional police skills for evil purposes.