Hugo Award-winning editor Gardner Dozois' annual anthology has long been considered the standard by which other best-of-the-year SF collections are judged. After two decades' worth of superlative science fiction, Dozois now presents a retrospective compilation culling from the last 20 years. Here under one banner is some of the finest work by the genre's leading authors, with a star-studded list of contributors that features among others: Stephen Baxter, Greg Bear, William Gibson, Terry Bisson, Greg Egan, Ursula K. Le Guin, Robert Reed, Robert Silverberg, Bruce Sterling , Charles Stross, Michael Swanwick, Gene Wolfe. A number of the selections are now considered classics. Some notable stories include:'Blood Music', Greg Bear's Hugo-winning exploration of nanotechnology.'Bears Discover Fire', Terry Bisson's tongue-in-cheek consideration of future ursine evolution.'The Left Hand of Darkness', Ursula K. Le Guin's coming-of-age SF tale. 'The Winter Market', in which William Gibson returns to the subject that made him a cultural icon, cyberpunk.With work spanning two decades, this is the most significant science fiction short story anthology published in years.