Question: What 1955 novel written by Patricia Highsmith did William Horberg produce a film adaptation?
Sentence (from "Purple Noon"): The film stars Alain Delon in his first major film, along with Maurice Ronet (as Philippe Greenleaf) and Marie Laforêt (as Marge); Romy Schneider appears briefly in an uncredited role as Freddie Miles' companion, and Billy Kearns (an expatriate American actor well liked in France) plays Greenleaf's friend Freddy Miles.
Relevant evidence: No