Exit Party

The multiverse—the hypothetical concept rooted in theoretical physics that our observable universe is only one of many—acts as the premise for many works of speculative fiction. In 1957, Princeton graduate student Hugh Everett III proposed what became known as the Many-Worlds Interpretation of quantum mechanics. Traditionally, physicists believed that a tiny quantum particle exists in a “probability wave” (a cloud of all potential states at once), and the moment you look at or measure it, the cloud suddenly "collapses" into just one real result, like rolling a die that lands on one number. Everett argued that the apparent “collapse” of a quantum wave function during measurement was an illusion. He theorized that every possible outcome of a quantum event actually occurs, each in its own branching universe. While many of his contemporaries disagreed with his findings, Everett “challenged the physics establishment of the day to reconsider its foundational notion of what constitutes physical reality” (Byrne, Peter. “The Many Worlds of Hugh Everett.” Scientific American, 21 Oct. 2008). His dissertation, overseen by Danish theoretical physicists, Neils Bohr, lay largely ignored until physicist Bryce DeWitt revived and popularized it in the 1970s. 

Subsequent cosmological models have proposed other multiverse frameworks. Andrei Linde’s chaotic inflation theory posits that a massive, rapid, growth spurt—which he called “inflation”—in the fraction of a second after the Big Bang created the cosmos we see today and, potentially, an endless multiverse. He theorized that “Instead of a universe with a single law of physics, eternal chaotic inflation predicts a self-reproducing, eternally existing multiverse where all possibilities can be realized” (Shackleford, Scott. “Worlds Without End.” Stanford Magazine, Nov./Dec. 2007). Swedish American physicist, Max Tegmark’s four-level taxonomy of parallel worlds builds on this theory, arguing that if space goes on forever, then if a person travels far enough past the solar system’s cosmic horizon, they will eventually find exact or slightly different duplicates of Earth. These models remain controversial—critics such as Paul Davies and George Ellis argue they are untestable and therefore unscientific—but they have provided authors of speculative fiction with rich material.

Science fiction imagined parallel worlds long before physicists formalized them. H.G. Wells’s Men Like Gods (1923) sent Edwardian motorists sideways into a utopian Earth, introducing a modern parallel-worlds story. Murray Leinster’s novella Sidewise in Time (1934) gave the subgenre its name and its basic grammar of overlapping timelines colliding across a single landscape. During the Golden Age of science fiction, writers rapidly expanded the device: Jack Williamson’s The Legion of Time (1938) staged a war between two mutually exclusive futures; Fritz Leiber’s The Big Time (1958) depicted agents battling across edited timelines; and Philip K. Dick’s The Man in the High Castle (1962) imagined an America that lost the Second World War, with characters dimly intuiting our own history through a novel-within-the-novel. Michael Moorcock’s sprawling Eternal Champion series, beginning in the 1960s, popularized the term “multiverse” within fantasy and sci-fi fandom.

Contemporary writers have continued to mine the premise. Larry Niven’s titular story in his collection, All the Myriad Ways (1968) interrogates the moral paralysis of infinite outcomes; Ursula K. Le Guin’s The Lathe of Heaven (1971) treats reality-shifts as psychological catastrophe; Neal Stephenson’s Anathem (2008) wove Everett’s proposed cosmology into monastic philosophy. Other more contemporary examples include Blake Crouch’s Dark Matter (2016) and Matt Haig’s The Midnight Library (2020), which have brought multiverse plots to bestseller lists, while films such as Everything Everywhere All at Once (2022) have elevated the concept in mainstream pop culture. The device endures because it externalizes the inner experience of regret, counterfactual thinking, and the roads not taken.

In Exit Party, Mandel draws on this long lineage. At Kareem’s get-together, James witnesses Saraya and her doppelgänger in two different outfits at once, and the party becomes what James calls a “door” (42) between two parallel universes. Nico arrives and stays, while Kareem disappears, never to return. Journalist Emily St. Martin notes that Exit Party’s “alternate realities are split like a nightmarish LP — the party in Silver Lake pops off on the A-side where, soon, most territories will be contested, and militias and gunfire will become ubiquitous. On the B-side, Ari […] is a high-ranking official of the Internal Intelligence Service, a ruthless police force of the totalitarian and surveilled ‘United State’” (St Martin, Emily. “Emily St. John Mandel’s Exit Party Is Heading to TV With Emma Stone Attached.” Los Angeles Times, 12 Oct. 2026), allowing Mandel to explore two of the possible futures to which the real-world political polarization and unrest she sees around her could lead.