
Original title, in magazine serial, was "Recruiting Station." Also published by Ace Books as "Earth's Last Fortress."
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A recruiting station; a storefront in the heart of a big-city downtown. Young men can volunteer to join the armies of a beleaguered new democracy overseas.
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But the recruitment is a scam. Each volunteer goes, not to the Calonian army, but through a pulsing machine which moves them hundreds of centuries up the time line, to become cannon fodder in a war which is shaking the universe.
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Two present-day humans are taking on this mammoth military machine. Their chances are miniscule. Their only hope is to save a few lives before giving up their own. But playing tricks with Time can lead to unexpected results.
Author

Alfred Elton van Vogt was a Canadian-born science fiction author regarded by some as one of the most popular and complex science fiction writers of the mid-twentieth century—the "Golden Age" of the genre. van Vogt was born to Russian Mennonite family. Until he was four years old, van Vogt and his family spoke only a dialect of Low German in the home. He began his writing career with 'true story' romances, but then moved to writing science fiction, a field he identified with. His first story was Black Destroyer, that appeared as the front cover story for the July 1939 edtion of the popular "Astounding Science Fiction" magazine.