Implied Spaces begins as what seems a fairly typical fantasy epic of the sword-and-sorcery variety, with a romantic traveler named Aristide, who bears a Stormbringer-like sword, and his companion, Bitsy, a talking cat, making their way through a gritty landscape that could have been lifted from World of Warcraft. But as with Matthew Woodring Stover's Heroes Die, fantasy trappings are soon pulled back to reveal science fiction: Aristide is a student of implied spaces investigating a pocket universe called Midgarth, modeled on gaming fantasies; his sword, Tecmessa, is edged with a wormhole that sends its unfortunate victims to a Limbo-like pocket universe; and his cat is the avatar of Endora, one of 12 vast AI computer platforms orbiting our sun.

Midgarth is a pretechnological world, and though its inhabitants share in many of the benefits of the advanced technologies Aristide and others in the original outside universe take for granted, such as virtual immortality conferred by the storage of regularly backed-up personalities and their downloading into fresh bodies when necessary, they are not aware of the outside universe or advanced technologies—or are aware of them only in culturally determined forms such as religion or magic. Thus Aristide is unpleasantly surprised when he encounters three priests of a heretofore unknown deity called Venger, each of whom is equipped with a weapon that, like his own, utilizes wormhole-based technology.

Out of the pocket, back in the macro-universe, Aristide and Bitsy soon realize that they have stumbled across a plot to eradicate free will from all the universes and forcibly unite their inhabitants under the thrall of a mysterious, amoral maniac.

A familiar tale told with panache

There is little in Implied Spaces that will surprise readers acquainted with the post-human space operas of Iain M. Banks, John C. Wright, Peter Hamilton and others of their ilk ... or, for that matter, with the far-flung futures of Jack Vance. But Williams is a first-rate storyteller with a talent for tight, twisty plots and complicated, even messy (i.e., realistic) character relationships. These talents make Implied Spaces his best work since the duology composed of Metropolitan and City on Fire, both Nebula nominees.

Here Williams delves deeply into the moral and psychological ramifications of the technologies touched on above. Aristide, who has been alive for many centuries, is rather old-fashioned by the standards of his society, not least due to horrific experiences many years earlier in a war fought by means of engineered plagues designed to subvert consciousness itself. Still scarred from these experiences, he appreciates perhaps more than any other living human being what is at stake in the new threat from Venger.

The hunt for Venger, which almost inevitably involves the possibility of a rogue AI and also serves to bring Aristide into perilous contact with an old flame, continues for nearly half the book, and as long as it does, the novel is hard to put down. After Venger's identity is established, however, an element of suspense departs from these pages, never fully to return, though Williams labors mightily to make up for it as the war between Venger and the rest of the civilized universe or universes ramps up and up and up.

Implied Spaces is not a major novel on the massive scale of Williams' Dread Empire's Fall trilogy. It's a little jewel of a book, its ambitions well suited to its size—with plenty of implied spaces of its own to discover ... and the hint of a sequel as well.