Jack Williamson 
Legion of Space 

They were the greatest trio of swashbuckling adventurers ever to ship out to the stars! There was giant Hal Samdu, rocklike Jay Kalam and the incomparably shrewd and knavish Giles Habibula. Here is their first thrilling adventure – the peril – packed attempt to rescue the most important person in the galaxy, keeper of the vital secret essential to humanity’s survival in the deadly struggle against the incredibly evil Medusae… The Legion of Space is the first self-contained novel in Jack Williamson’s epic Legion of Space series, an all-time classic of adventurous science fiction to rank with 'Doc’ Smith’s Lensman saga and Isaac Asimov’s Foundation trilogy.