Long dismissed as a technology of the distant future, artificial intelligence was a project consigned to the fringes of the scientific community. Then two researchers changed everything. One was a 64-year old computer science professor and the other was a 36-year-old neuroscientist and chess prodigy. Though they took very different paths, together they helped catapult AI to the forefront of our daily lives and created a business worth billions. This is the story of a technological revolution and the arms race it has sparked among companies such as Google, Microsoft, Facebook, and Elon Musk's OpenAI. It is also the story of the struggle between international powers, shareholder value, the pursuit of scientific knowledge, and the very human concerns about privacy, security, bias and prejudice that AI raises. New York Times Silicon Valley journalist Cade Metz draws on unparalleled access to create an extraordinarily vivid account of an ongoing technological revolution. And he poses the question that will dominate the next half-century: where will AI take us next?