The Challengers pursue Roc, a would-be conqueror. Using "mind over matter," Roc runs them off by mentally conjuring a giant ape and missile. Fighting fire with fire, the scientist who created the mind-over-matter machine gives Ace similar powers. They battle with a conjured dragon, knight, giant vacuum cleaner, mirrors, and more. Finally Ace uses spinning circles to hypnotize and capture Roc.; A prospector uncovers a monster, an indestructible one-eyed walking box that tramples villages. The Challengers's weapons don't make a dent. And June mysteriously sabotages their efforts! Prof finally guesses the monster's one eye is solar-powered. Pursued until sunset, the monster expires. June had run a computer program that predicted the Challengers would die, hence her sabotage. But her efforts changed the equation, so she saved the day!