Brian Herbert and Kevin J. Anderson based their sequels to original Dune series on research material composed by Frank Hebert before his death. Are there any sources that describe how much material was found and what it contained? Anything that can help to evaluate how true both authors kept to the original vision. Answer I started with the Brian Herbert wikipedia article 's references section. There are a lot of sources here but here are the ones I think are the most significant. First there's this archived blog post by Kevin J. Anderson where you could see those disk : To the left, I'm posting copies of the actual IBM diskettes containing the files, with the labels "Dune 7 Outline" and "Dune 7 Notes" in Frank Herbert's own handwriting. And lower on the blog post you could read : When Frank wrote HERETICS and CHAPTERHOUSE he obviously intended to complete the story. He had planned an entire epic that tied his chronicles back through his whole pr...