Complex sentence: The Spacing Guild is an organization in the fictional "Dune" universe developed by science fiction author Frank Herbert in a series of novels starting in "Dune" and ending with "Chapterhouse Dune".
Split into simpler sentences: The Spacing Guild is an organization in the fictional "Dune" universe created by Frank Herbert. It plays a in a series of science fiction novels starting in "Dune" and ending with "Chapterhouse Dune".