 The novel and the screenplay were both based on an episode in the  radio series, "The Lives of Harry Lime", in which Welles played his  Harry Lime character as rather less villainous that he was in "The  Third Man". In "Mr. Arkadin", the Harry Lime character is renamed  "Guy van Stratten", and Welles plays Arkadin. The radio episode was  number 37 in the series, entitled "Man of Mystery," and first  broadcast on 11 April 1952. The introduction to the episode also  describes the movie: "One late afternoon a couple of years ago, a  plane was sighted about seventy miles out of Orly Airport in Paris.  It was a private plane, medium sized, and nobody was in it; nobody  at all. The plane, keeping its course steadily toward Paris, was  flying itself. Why was it empty? Who had been flying it? And why,  and under what circumstances, had they left it? Why? Thereby hangs a  tale."