How would ancient Vikings react to a gun-wielding giant with flaming red hair? What would a modern cop do in a feudal world where gunpowder was considered a benediction of God? What if Scipio Africanus never lived to challenge, or kill, Hannibal at Zama? The probabilities are endless-an infinite number of ways to replay the same scene, over and over again. War transmuted to its highest magnitude, ripping through the very fabric of time. Features stories by Poul Anderson, Anne McCaffrey, Harry Harrison, Keith Laumer, John D. MacDonald, Bob Shaw, H. Beam Piper, and Randall Garrett.
Martin Harry Greenberg was an American academic and speculative fiction anthologist. In all, he compiled 1,298 anthologies and commissioned over 8,200 original short stories. He founded Tekno Books, a packager of more than 2000 published books. In addition, he was a co-founder of the Sci-Fi Channel.
For the 1950s anthologist and publisher of Gnome Press, see Martin Greenberg.
While I liked most of the short stories, some felt really contrived and "Gary Stu"-ish. For instance, in the first story, the protagonist happens to be a crack-shot with his pistol, and not only that, when he appears in a prehistoric time, he "happens" to have extensively practised spear combat. Yeah.
The second stories protagonist is a police officer, so obviously knows to shoot, but also is a perfect horse-rider, knows how to make gunpowder, is a (very) able swordfighter and turns out to be an excellent leader.
Nonetheless, I really liked the stories, and not all of them are like that, so I'd recommend it.