In his last feature film released during his lifetime, Orson Welles delights in examining the fine line between truth and illusion, art and lies. The story, which intertwines different narratives, starts with Elmyr de Hory, a famous art forger, and Clifford Irving, author of a false autobiography of Howard Hughes, to expose forgeries and forgers — including the filmmaker himself who, by appearing as both narrator and participant, adds layers of illusion to the film.