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
Lewis Gilbert Lewis Gilbert Lewis Gilbert (6 March 1920 – 23 February 2018) was a British film director, producer and screenwriter, who directed more than 40 films during six decades; among them such varied titles as "Reach for the Sky" (1956), "Sink the Bismarck!" (1960), "Alfie" (1966), "Educating Rita" (1983) and "Shirley Valentine" (1989), as well as three James Bond films: "You Only Live Twice" (1967), "The Spy Who Loved Me" (1977) and "Moonraker" (1979). Lewis Gilbert was born in Hackney, London, to a second-generation family of music hall performers, and spent his early years travelling with his parents, Ada (Griver), who