After Maj. William Allison (Robert Clarke) pilots a test craft through a suborbital space-time wormhole, he returns to his base, only to discover that it's 64 years later, a plague has decimated the planet, and the survivors have been rendered sterile. Suddenly knocked unconscious and taken to an underground city, Allison finds himself called upon to mate with a mute princess (Darlene Tompkins) to repopulate Earth in this cautionary sci-fi tale.