[![enter image description here][1]][1]

[*The Best from Fantasy and Science Fiction, Sixth Series*](http://www.isfdb.org/cgi-bin/pl.cgi?191001), edited by [Anthony Boucher](https://en.wikipedia.org/wiki/Anthony_Boucher). This is the 1962 Ace paperback edition of an anthology originally published in 1957. The cover by [Ed Valigursky](http://www.pulpartists.com/Valigursky.html) is inspired by [Poul Anderson](https://en.wikipedia.org/wiki/Poul_Anderson)'s story ["The Man Who Came Early"](https://en.wikipedia.org/wiki/The_Man_Who_Came_Early). Note the letters MP on the soldier's helmet.

  [1]: https://i.sstatic.net/NQD4w.jpg