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
Edwin Shirley illustrious Tour Manager and the two of them wrote the book on how to party on tour." Having built a successful trucking company, Shirley started a new company Edwin Shirley Staging which built stages for a number of large concerts including Live Aid in 1985. Shirley left both companies in the 1990s. While looking for rehearsal space in East London, Shirley viewed Three Mills Island, and realised the potential to develop a film studio there. After meeting with Peter Bazalgette, Shirley secured the site as the location for the first "Big Brother" reality TV programme, which went on to become