every single one of these collections is essential reading for true fans of science fiction short stories... each lengthy volume has a stellar array of all mini-genres and areas of powerfully influential science fiction: hard science, speculative, steampunk, alien invasions, apocalyptic/post-apocalyptic, space opera, fantasy, aliens, monsters, horror-ish, space travel, time travel, eco-science, evolutionary, pre-historic, parallel universes, extraterrestrials... in each successive volume in the series the tales have advanced and grown in imagination and detail with our ability to envision greater concepts and possibilities... Rod Serling said, "...fantasy is the impossible made probable. science fiction is the improbable made possible..." and in the pages of these books is the absolute best the vastness of science fiction writing has to offer... sit back, relax, and dream...