In its 880 pages, Neal Stephenson's Fall; or, Dodge in Hell navigates many of the themes the science fiction author has become known for. The history, and future, of science. How knowledge engenders power, and how that power perpetuates itself. How technologies that sound far-fetched are in fact inevitable, derived as they are from a centuries-long process of incremental breakthroughs.

What’s unique to this go-round is that Stephenson’s pet ideas about our digital lives and afterlives overshadow his book's urgency. Nearly 30 years ago, Stephenson envisioned the metaverse; at the start of Fall, he sees a culture cleaved in two, its divisions reinforced by AR-enabled filter bubbles. It's a pressing, plausible future—and one Stephenson ultimately leaves unexamined.

Early in Fall, wealthy game-studio founder Richard "Dodge" Forthrast dies. Mostly. After a medical procedure goes awry, his family discovers that Dodge's will dictates he be cryogenically preserved. The book unfolds from there: A viable brain-scanning technology emerges, and Dodge's "connectome"—the full array of his brain's neural connections—gets scanned and saved. When his connectome stutters into digital wakefulness, it begins to shape a world around itself, giving rise to what those in meatspace come to call Bitworld.

The uploaded mind is a well-loved trope in sci-fi, but it's often treated as a "hey, humans can do this now" sort of innovation. In Stephenson's hands, that innovation is very much in progress. It stumbles from infancy into pubescence, with Bitworld (and its denizens) slowly gathering power and fidelity throughout the book until it becomes a death-haven for those able to afford it. All that power doesn't come cheap. Running Bitworld requires quantum leaps in quantum computing, and the world outside slowly turns into the engine running Bitworld.

As does the book. Fall spends more and more of its time in Bitworld, watching its souls reshape the space in ways both archetypal and transgressive—until about halfway through, when the narrative balance tips, becoming a fantasy novel about a quest inside the still-evolving Bitworld. Stephenson is going for something in this final third of the novel. Maybe it’s a repudiation of genre lines, showing purists that sci-fi and fantasy aren’t so different after all. Maybe it’s an ode to the power of collective storytelling, playing out how humans inevitably return to their own creation myths. In the world outside of Bitworld, little of that matters—but the more time spent in Bitworld, so too does that outside world matter less and less. In shrinking and spacing out those returns to meatspace, the book begins to stall, and eventually unravels.

What's most disappointing about Fall's fall into its parallel prehistory is that it leaves a different, more urgent book unwritten—one in which Stephenson wrestles with the chaotic fallout of today's social internet. Dodge's death may open the book, but disinformation catalyzes it: a massive hoax that makes the world believe a nuclear detonation has wiped out the small town of Moab, Utah. The perpetrators pull off their put-on with terrifying ease, making recent election-season shenanigans seem like an innocuous appetizer. (Stephenson, who wrote much of that part of the book before 2016, has said he had to scale much of it back as he "discovered that the future was way ahead of me.")

Peter Rubin writes about media, culture, and virtual reality for WIRED.

Jumping forward a dozen years or so, the reader finds that Moab has, in fact, become the flashpoint for what Stephenson elides as "the Facebooking" of America. AR glasses are by now as widespread as those of us in the 2010s assumed they would be, delivering newsfeeds directly to people's eyes; however, unless you can afford a human editor or you pool your money with others to subscribe to a feed with decent AI filters, that feed is algorithmically determined to keep you in what one character calls a "personalized hallucination stream"—one synced with your pulse, how fast you blink, and other markers.