HAL 9000, the sentient computer in 2001: A Space Odyssey, offers an ominous glimpse of a future in which machines endowed with artificial intelligence reject human authority. After taking control of a spacecraft and killing most of the crew, HAL responds to a returning astronaut’s order to open the ship’s pod bay door in an eerily calm voice: “I’m sorry, Dave, I’m afraid I can’t do that.” In the recent science-fiction thriller Ex Machina, the seductive humanoid Ava tricks a hapless young man into helping her destroy her creator, Nathan. Her machinations lend credence to Nathan’s dark prediction: “One day the AIs are going to look back on us the same way we look at fossil skeletons on the plains of Africa. An upright ape living in dust with crude language and tools, all set for extinction.”