When two brilliant misfits bond at an elite Chicago private school--one a white legacy kid named Todd Keane and the other, Rafi Young, a Black scholarship student from the South Side--their friendship seems as boundary-breaking and limitless as the 3,000-year-old board game that brings them together. For a time, not even simultaneously falling in love with Ina Aroita, who grew up in naval bases across the Pacific, shakes them. Until finally it does, with a betrayal that launches all three of them on radically different paths. Rafi disappears into literature, and Ina into art. Todd, who once dreamed of escape into the world beneath the surface of the ocean, revealed to him by the legendary Canadian diver and marine biologist Evie Beaulieu, becomes instead one of the most powerful tech billionaires on the planet whose social media empire, Playground, is remaking the global order with its AI breakthroughs. But not even wild success can insulate Todd from mortality. As illness eats away at the brain that built it all, he dreams of the life that could've been and the relationships he should never have let go. Before Todd's final act is up, past loves and present ambitions collide on the ravaged Polynesian island of Makatea, where an unnamed corporation hopes to build the first floating, autonomous city on the open sea.