Detectives Nina Suresh, Bobby Day and Alec Wayfield investigate when family doctor Angela Benton is murdered in a children's playground. The apparent killer, schizophrenic Jacob Appley, is later found dead but Alec disbelieves Doctor Crowley's view that it was suicide. Ageing, ailing Bobby befriends Lucy Cannonbury, a witness and friend of the victim, whilst Nina, dumped by boyfriend Dennis, turns to Alec. The detectives get wind of a bogus policeman, Galen, of whom there is no official record, and whom they name the Ghost Detective before a postcard arrives at the police station, saying Look At Angela's Past. This leads to Dusseldorf, home of Angela's ex-partner Ruben Lucana, and detective Linda Felber, who finds a dead man at Ruben's house. Then another card arrives for Bobby with the words You Have No Idea What You Are Up Against.
—don @ minifie-1