If the United States collapses in the near future, you’ll no doubt be tempted to point a few fingers. Just don’t blame Emily St. John Mandel (emilystjohnmandel). As Covid tore across the planet, Mandel became something of a pandemic prophet for writing the hit 2014 novel, “Station Eleven.” Journalists and everyday Twitter users alike looked to her for guidance as they hunkered down at home, desperate for someone—anyone—to tell them what was happening, and what might come next. Now, Mandel is out with a new book, “Exit Party,” that documents the interwoven lives of people living in two different, near-future versions of the US: A violent, post-civil-war free-for-all, and a totalitarian state where surveillance runs roughshod over a paranoid populace. She started writing the book in 2022, when polarization and political extremism were already surging—but well before the era of Trump 2.0, widespread ICE raids, and tech-infused surveillance we’re living through today. “Exit Party” is a t...