George Lucas asked MacGregor to continue writing original novels for Bantam Books. These were geared toward an adult or young adult audience, and were prequels set in the 1920s or early 1930s after Jones graduates from college. Of the film characters, Lucas only permitted Marcus Brody to appear. He asked MacGregor to base the books on real myths, but except for the deletion of a sex scene, the writer was given total creative freedom. His six books – "Indiana Jones and the Peril at Delphi", "Indiana Jones and the Dance of the Giants", "Indiana Jones and the Seven Veils", "Indiana Jones and the Genesis Deluge", "Indiana Jones and the Unicorn's Legacy", and "Indiana Jones and the Interior World" – were published from February 1991 to November 1992. "The Genesis Deluge", published in February 1992 and featuring Noah's Ark, was the best-selling novel; MacGregor felt this was because it "had a strong following among religious-oriented people [...] because they tend to take the Noah's Ark story to heart and think of it as history and archaeological fact, rather than myth." MacGregor's favorite book was "The Seven Veils", which featured real-life explorer Percy Fawcett and the death of Indiana's wife, Deirdre Campbell.