David Duncan didn't begin to write full-time until the age of 33, in 1946, after ten years of work in government administration and public services. He began screenwriting in 1953 and started writing science-fiction movies after one of his SF novels, "Dark Dominion", was serialized in "Collier's" magazine. His favorite among the sci-fi films he wrote is The Time Machine (1960), "by a huge margin."