Demon Seed is a science fiction and horror novel by the best-selling author Dean Koontz first published in 1973, and then completely rewritten and republished in 1997. Though Koontz wrote both versions and they share the same basic plot, the two novels are very different. The earlier version has a dual narrative, with some chapters written from the perspective of Susan, the story's heroine, and others based on the observations of Proteus, the rogue computer that imprisons her. The later version is written entirely from the point of view of Proteus. A film adaptation of the book was released in 1977.