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
Educating Rita (film) instead have children. Rita struggles to fit into a new educated middle-class existence in academia, while seeking a 'better song to sing'. Rita's original preconceptions that the educated classes have better lives and are happier people are brought into question throughout the film through Frank's failing social life and alcoholism and also her flatmate Trish's attempted suicide. Rita, her search, and her search's meaning for her, all evolve as she adapts to academia and grows as a person. Lewis Gilbert says it was difficult to raise finance for the film. "Columbia wanted me to cast Dolly Parton as Rita". Julie