Five Red Herrings (1975)
Director:Robert Tronson
Writer:Dorothy L. Sayers (novel), Anthony Steven (writer)
The story is set in Galloway, a part of Scotland popular with artists because of its landscapes. Sandy Campbell is a talented painter, but also a notoriously quarrelsome drunkard. When he is found dead in a stream, with a half-finished painting on the bank above, it is assumed at first that he fell in accidentally, fracturing his skull. Lord Peter Wimsey points out the inconsistency which makes it impossible for Campbell himself to have worked on the painting. (Sayers deliberately leaves the reader to work out what exactly the clue is.) Campbell's death is now a murder case.
The Five Red Herrings is the Peter Wimsey story which is most obviously set as a puzzle for the reader. There are only six suspects to deal with, and Wimsey has no emotional involvement. (Although, having alerted the Police to Campbell's murder, he subsequently reflects that Campbell was a man anyone might feel justified in killing, and that the six suspects are all generally decent people. He nevertheless resolves to uncover the truth, so that the five innocent artists should not live under lifelong suspicion.)