Exit Party by Emily St John Mandel

Exit Party by Emily St. John Mandel begins in Los Angeles in 2031, after the collapse of the United States and the withdrawal of peacekeeping troops. At a crowded party, an uncanny doppelganger appears and the host suddenly disappears. Ari Waker begins investigating the strange night, setting off a story that moves across a fractured future world, from California to Greece, Paris, and the moon, while exploring surveillance, safety, resilience, and the instability of reality itself.