Even in a tech world crowded with visionary leaders, Demis Hassabis is recognized as a special case. Born to working class, immigrant parents in North London, a chess prodigy by five and wizard coder in his teens, he turned down a seven-figure job offer from a video-game studio to study science at Cambridge. Long before the current obsession with AI, he founded the path-breaking company DeepMind in order to pursue a single, audacious goal: the dream of artificial superintelligence, which would solve humanity?s hardest problems, change life and work as we know it, and perhaps even unlock the deepest mysteries of the Universe. For his scientific achievements, he won a Nobel Prize in 2024, and his company, now Google DeepMind, is considered the tech giant?s engine room. For the past three years, Sebastian Mallaby has had unprecedented access to Hassabis and DeepMind, conducting hundreds of hours of interviews with him and his inner circle as well as detractors and rivals at other companies. The result is a revelation-packed portrait of a singular mind and a historic reckoning with the AI revolution, a shift potentially more significant than any since the dawn of complex thought 70,000 years ago. As Mallaby chronicles, DeepMind is locked in an arms race with Silicon Valley competitors to build artificial general intelligence, and thereby become the keeper of humanity?s future. Yet this is not a Silicon Valley story. Hassabis has remained in Britain, and unlike his rivals, his aims are not wealth and power but scientific enlightenment. Like them, however, he is haunted by the memory of Robert Oppenheimer, the creator of the atom bomb. He aims to control the technology, but the technology may ultimately control him ? and humanity writ large.