In 1948 author Graham Greene was in Vienna getting a tour of the city, its back alleys, less-reputable nightclubs, and even its sewers. He was also introduced by actress Elizabeth Montagu to Peter Smolka, the central European correspondent for The Times. Greene was working on a novella that would become a screenplay called The Third Man. Greene sold the film rights to producers Alexander Korda and David O’Selznick.

In the story a man named Holly Martins comes to Vienna to accept a job with his friend Harry Lime, only to learn that Lime has died. Martins is a writer. He’s told Lime was killed by a car while crossing the street.

​​At Lime's funeral, Martins meets two British Royal Military Police: Sergeant Paine, a fan of Martins' books, and Major Calloway. Martins thinks the death is suspicious, so he stays in Vienna to investigate the matter.

Orson Welles was cast as Lime with longtime Mercury Theater friend Joseph Cotton cast as Martins. Principal photography began in Vienna in early November of 1948 and lasted for six weeks. The rest was done around London and completed by March of 1949.

Then-unknown composer Anton Karas was hired to create the musical score, performing it on a zither.

The film was released in the UK in September of 1949, quickly becoming that year’s most popular.

When released in the U.S. audiences loved it. Time wrote that the film was "crammed with cinematic plums that would do Hitchcock proud—ingenious twists and turns of plot, subtle detail, full-bodied bit characters, atmospheric backgrounds that become an intrinsic part of the story, a deft commingling of the sinister with the ludicrous, the casual with the bizarre.”

At the 1951 Academy Awards, the film took home the award for Best Black and White Cinematography, while at the British equivalent, it won for Best British Film.

In the meantime Welles and Tyrone Power made The Black Rose in 1950, directed by Henry Hathaway. Welles played Mongolian warrior Bayan of the Hundred Eyes. Hathaway, who liked Welles, later said the casting was poor, with Welles purposely outwitting people during shooting.

While in England making The Third Man, Orson Welles became acquainted with Harry Alan Towers. Towers was a thirty-year-old radio producer whose company, Towers of London, was heavily into syndicated productions in British, American, Australian, and Canadian markets. His anthology series Secrets of Scotland Yard had proven that there was a lucrative market for high-end entertainment and, in Welles, he saw a personality and a talent that could quickly make his production company a leading one.

Towers and Greene had the same literary agent. Finding out that Greene hadn’t sold Harry Lime’s character rights when he sold the screenplay, Towers quickly bought the rights to the character with plans to put a syndicated radio series into production.

Welles signed with Towers to produce The Adventures of Harry Lime. They were prequel stories showcasing some of the more good-hearted things Harry Lime was supposed to have done.

Only sixteen of the episodes were acquired and broadcast by the BBC. It was the first time that the BBC broadcast episodes of a dramatic series that it did not produce. The full fifty-five episodes were syndicated to radio stations in the U.S.

Welles is credited as the author of ten scripts, including the first episode, “Too Many Crooks” which aired on August 3rd, 1951. The fifth episode was called, “Voodoo,” something Orson Welles had a lot of experience with, dating back to his time in South America during World War II.