The ever-provocative Ellison is at the top of his form in these 21 stories and essays, dynamiting fault lines where the fantastic erupts into the everyday and jolting interfaces between the mythic and the mundane. None of the characters in this outstanding collection is invulnerable to slippage, that sudden disorienting sense that ""the universe shifted over one notch"": not the fugitive criminals who discover that they can't escape a rendezvous with the supernatural in ""Sensible City""; not the dinosaurs made extinct by extraterrestrials in ""The Dreams a Nightmare Dreams""; not even the gods no one believes in any more in ""Chatting with Anubis."" Ellison's loquacious protagonists are so personable, and their lives and appetites so appealingly ordinary, that one is easily beguiled into accepting their outrageous revelations--for example, that life's random injustices are the work of cosmic string-pullers on a lark, as in ""The Man Who Rowed Christopher Columbus Ashore,"" or that computers are a vampiric life form that feed through our fingertips, as in ""Keyboard."" An antic spirit pervades most of the stories; but even when playing the court jester, Ellison can be deadly earnest, hurling barbed commentaries dripping with insight. ""Mephisto in Onyx"" explores racial prejudice through its conceit of a black mind-reader summoned to interrogate a white serial killer. ""The Few, The Proud"" and ""Pulling Hard Time"" are sardonic inquiries into social hypocrisy that divulge the true motives of men hailed by the public as heroes or vilified as villains. Ellison has purged his writing of the excesses and indulgences that burdened the stories in Angry Candy (1988). These newer efforts are, by contrast, as sleek and on-target as a cruise missile. (Aug.) FYI: Slippage was previously published in a limited edition by Mark Ziesing.