Diskan Fentress, mutant son of a space explorer, felt himself out of place on the luxury worlds of civilized space. It was not until he stole a space ship and a travel key to the unexplored planet of Mimir that he first felt his latent powers to be of some worth. For Mimir was a world of strange relics, of beasts that were not beasts, and of a ruined city whose shadows spoke of a higher and weirder civilization than any the galaxy had yet discovered. And it was to fall to Diskan's lot to mee THE X FACTOR head on -- and to settle a planet's fate with his reaction