Marlowe and three other astronauts get zapped into the future during a test flight and land on Earth in the year 2508. The world has experienced nuclear destruction and its surface is overrun by mutant cyclopes. The only real connection to civilization is an underground community of elfish beings who befriend the spacemen. Together they battle the cyclopes and destroy giant spiders that roam the decaying planet. The astronauts, destined to live in the future, make no attempt to leave and instead help the dying race rebuild. The costumes of the underground dwellers were designed by Vargas, the famed pinup illustrator for Esquire and Playboy.