The Independent -- London:

In the end, The Extremes is perhaps a nightmare, perhaps not. Most extraordinarily, for most of its length it is both. Teresa is both a meat-puppet victim of the new world, and one of those who write our futures for us. Swift, haunting, cruel and kind, The Extremes is a guidance manual for the maze we face.

Vector:

The Extremes, whether or not the reader anticipates the twists as they occur, is immensely satisfying in its final resolution. It deals with questions -- Is my reality your reality? How can we make sense of random, hurtful events? -- that haunt us all. The concept of virtual reality might have been invented in order for Priest to use it in this way. The best yet. Read it and re-read it.

SFX:

All of Priest's familiar raw material is set out here, and the author's adherents will relish the seductive skill with which he draws the reader into a tangled web of relationships, phenomena and understated sensuality. Priest's appeal as ever centres on his people and their relationships, their struggles to explore their world and their own psyches, and the way they're marooned in British culture: narrow, cramped, depressing, but layered deep by time. The Extremes is a novel of violence and reality of extraordinary power and ambiguity. A vital contribution from a key British writer. Recommended.

Interzone:

Priest has always been an unusually meticulous writer, intellectually as well as aesthetically rigorous in the construction of his characters and plots, and The Extremes reaps the benefit of all his experience in this regard. Most characters lost in mazes like the one which confronts and claims Teresa Simons -- and I doubt that there has ever been another quite so fiendishly complex -- either come apart under the strain, reconcile themselves to being hopelessly lost forever, or avail themselves of a convenient deus ex machina laid on by a desperate auteur. Teresa and her auteur are made of sterner and more ingenious stuff, and they make a far better fist of negotiating their way to the heart of the labyrinth than any rival I have encountered. Teresa's odyssey is mapped with the minutest care, and her personality is established with similar scrupulousness in order that the reader can be with her every step of the way. The existential vertigo which grips her when she realizes, reluctantly, that she has lost her way between the imaginary and the real, is communicated to the reader with consummate skill and considerable impact -- and her response is tactically brilliant as well as authentically heroic. The Extremes is undoubtedly his best yet, and no one coming to the theme for the first time could possibly have wrought such a tour de force.

New York Review of Science Fiction:

Virtual reality has been a science-fiction toy for years, brought out whenever a writer wants to play with reality. Here, perhaps for the first time, it becomes a precise surgical instrument slicing through our slender grip on who and what and where we are. As he has done triumphantly in The Affirmation and The Prestige, Priest quietly overturns everything we might rely on when we look for the surety of our own identity, the solidity of our world. Whether this makes the book science fiction is, of course, another matter. In the early 1980s Priest famously left science fiction, despite going on to write such haunting books as The Affirmation and The Glamour, which teased our notions of reality. He has gone on record as not wanting The Extremes to be published as science fiction, more, I think, because he is afraid of the narrow expectations such categorization brings rather than from any dislike of the genre. But after winning the World Fantasy Award as well as the mainstream James Tait Black Memorial Award for his previous novel, The Prestige, and with the powerful and at times harrowing take on virtual reality that he achieves with The Extremes, Priest has once again placed his work at the centre of what the genre is doing today.

Locus:

[A] novel of deep moral ambiguity, written with a compelling urgency and interestingly complex characters. The strength of The Extremes comes in part from displays of narrative virtuosity, in part from the claustrophobic, murder-trapped setting of Bulverton, and in part from the vulnerable and driven character of Teresa herself. But a good part of the novel's effect also derives from its judicious and -- despite all the violence -- understated use of the VR theme. This is not a novel of cybernetic Rapture like Dennis Danver's Circuits of Heaven last year, nor is it a tour de force of life in the software lane like much of Greg Egan, nor is it in the least Gibsonian. Instead, using VR as nothing more than an instrumentality, it is a novel that suggests in compelling and provocative ways that reality may in part be formed by memory, and that experience is not always what we think it is.

Publishers Weekly:

A forensic thriller with a strong science fiction element, Priest's novel provides suspenseful, intelligent entertainment. Priest (The Prestige) keeps one eye on his suspenseful plot, another on the SF angles that underpin it, and a third, camera-eye on the real implications of world-wide instant communication, virtual reality and media-driven violence. If his lingo can get a bit thick ("It's the same thing, in algorithmic terms, as your basic what-the-hell symbolic adumbration") his plot will keep most readers raptly amazed.

Science Fiction Chronicle:

Priest constructs his nightmare scenario carefully, unobtrusively, and effectively, drawing the reader into his created world just as his characters are drawn into virtual reality. It's an early front runner for best novel of the year.