How Roger Zelazny's Lord of Light transformed into the CIA's Argo covert op

To facilitate the return of six US diplomats trapped in Iran, during the 1979 hostage crisis, CIA technician Tony Mendez concocts an incredible cover story: they're part of a film crew, scouting out locations in the Islamic republic for an epic science fiction movie. But one core prop is hard to find at short-notice: a convincing, ready-to-shoot screenplay.