Fictionalized but true to the salient facts, Zarathustra Stone relates the story of the day Friedrich Nietzsche thought the thought that changed his life, and that would, he believed, alter the course of western intellectual history. The Eternal Recurrence of the Same. Eternal Return. The narrative explains imaginatively the origin of Nietzsche's idea, not only its philosophical roots, but its biographical, emotional, and psychological sources as well.