One source for Flash Gordon was the Philip Wylie novel When Worlds Collide (1933). The themes of an approaching planet threatening the Earth, and an athletic hero, his girlfriend, and a scientist traveling to the new planet by rocket, were adapted by Raymond for the initial storyline. Raymond’s first samples were dismissed for not containing enough action sequences. Raymond reworked the story and sent it back to the syndicate, who accepted it. Raymond was partnered with ghostwriter Don Moore, an experienced editor and writer. Raymond’s first Flash Gordon story appeared in January 1934, alongside Jungle Jim. The Flash Gordon strip was well received by newspaper readers, becoming one of the most popular American comic strips of the 1930s.