Emily St John Mandel's seventh novel, Exit Party, opens in Los Angeles in 2031, at a gathering where bizarre things happen. Doubles of some guests appear. Someone else disappears altogether. From there, the novel alternates between two potential future Americas — one riven by the chaos of civil war, the other a surveillance state.

The premise has roots in a dream Mandel had as a child, one that stayed with her for decades. "I was trying to find my dad in a crowd, and there were other people who looked like him but weren't him," she told the Guardian. "It just kind of struck my imagination."

Some forty years later, that childhood nightmare — the wrong double, the missing person — has become the organising image of her new book. The doubling extends to the nation itself: Mandel does not chart one future America but two, each a plausible answer to the political fractures of the present.

The author's question, posed in the interview accompanying the novel's publication, is blunt: "When half the electorate disagrees on basic reality, how do you come back from that?" It is the question Exit Party dramatises through its two alternate timelines, in which the United States either descends into civil conflict or hardens into a state of surveillance.

Readers know Mandel as the writer whose hit novel Station Eleven seemed to predict the pandemic. Published years before Covid-19, the book traced a devastating flu pandemic and the world that followed, and its resonance with 2020 made her one of the most discussed novelists of the period. Mandel herself acknowledges only a "tiny bit" of clairvoyance.

With Exit Party, she shifts from pandemic fiction to political futures, a move that places her among the novelists now treating the United States' next decade as speculative territory. The book's structure — a party gone strange, then a fork into two Americas — suggests that Mandel's world-building, the quality that made Station Eleven distinctive, now operates on the scale of a nation rather than a shattered globe.

The themes she returns to in conversation remain consistent with her earlier work: chance, world-building, and the unsettling sense of having glimpsed what comes next. The difference is the proximity of the setting. Los Angeles, 2031, is not a distant apocalypse but a near future, close enough that its two outcomes — civil war or surveillance — read as extrapolations rather than fantasies.

Exit Party arrives as Mandel's standing has never been higher, and it poses her most direct question yet about the country she left as a Canadian-born writer. Whether readers find her two futures pessimistic or cautionary, the novel's wager is clear: fiction can test the paths a divided electorate might take before reality chooses one.