The Riddle of the Sphinx (Inside No. 9) was characterised by Pemberton as a thriller in the style of Anthony Shaffer's 1970 play "Sleuth", while Shearsmith identified the episode as particularly theatrical, in the style of "Sleuth" and Ira Levin's 1978 play "Deathtrap". BBC executives, according to Shearsmith, saw the episode as a cross between "Sleuth" and Willy Russell's 1980 play "Educating Rita" that read as if it had been authored by psychopaths. The executive producer Jon Plowman suggested that the first half of the episode plays out like a radio play. The word-play and tea-drinking in this part of the episode are, in the writers' opinion, very
Valentine and Orson a European success for the tale. The works of François Rabelais have a number of echoes to the romance. Nancy Ekholm Burkert wrote and illustrated a version of the story in 1989, in which the story is told through the lens of a traveling group of players (including two brothers) who bring the story to a village in Flanders in the Middle Ages. Valentine and Orson Valentine and Orson is a romance which has been attached to the Carolingian cycle. It is the story of twin brothers, abandoned in the woods in infancy. Valentine is brought up as a knight