Elon Musk has claimed that AI is humanity’s “biggest existential threat.” Paradoxically, Musk is also working to create artificial intelligence. Why? Jill Lepore tours through a century of imagined robot rebellions, and argues that these stories are never only about robots. So what’s Elon Musk really afraid of when he wrings his hands over AI? In this final episode, Lepore argues that while Musk may be a visionary, “every piece of Muskism has origins in a future foretold in science fiction, long, long ago, as a cautionary tale.”