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
Rita Montaner nearly four years: the longest-running contract of her career. Mongo Santamaría commented: "This launched the era of the Cuban cabaret super-productions". Montaner continued to do theater work whenever her radio show was off the air. In 1955 she triumphed as Madame Flora in the opera "La Medium" by Menotti, and in 1956 in the comedy "Mi querido Charles". Beginning in 1954, she co-starred in the comedy television program "Rita y Willy" with Guillermo Alvarez Guedes. In the late 1940s and early 1950s, she acted in numerous Mexican movies of the Rumberas film genre. These are the films Rita appeared in