An attempt to wrest fantasy from a science-fiction backdrop--or vice versa--from the author of Voyage of the Fox Rider (1993), etc. Some years from now, the world has been depopulated by a dreadful plague. A group of expert fantasy garners, the Black Foxes, gathers in Tucson, Arizona, in order to field-test the ultimate role-playing fantasy game: a virtual reality created by Avery, an artificial intelligence, so real that the garners will actually become their fantasy alter egos. Thus, Dr. Caine Easley becomes healer Kane; eco-investigator Alice Maxon becomes pathfinder Lyssa; rich sponsor Arthur Coburn becomes retired thief Arton; and so forth. Their adventures will take place in Mithgar, McKiernan's previously invented fantasy stamping ground. But then a terrible storm strikes, knocking out power and driving Avery crackers. As the backup battery power ebbs away, project head Toni Adkins and her team make frantic but unavailing attempts to extract the Black Foxes from Mithgar, while, in the game itself, mad Avery, calling himself the Dark God, will stop at nothing to win. Finally, the Foxes defeat Avery and emerge in the nick of time, only to find they've acquired in reality the powers they possessed as their fantasy alter egos. Though McKiernan has improved since his dire imitation-Tolkien days, this clanking and bloated yarn amounts to little more than a talky belaboring of what-is-reality? notions previously explored by dozens of other writers.