Space satellite "Space Master X-7" returns to earth carrying a Martian fungus, which, in a lab mishap, reveals a creepy penchant for human blood. Tasting human blood and tissue, the "space rust" grows into a blubbery glob of oozing slime, claiming a lab scientist as its first victim just after the scientist and his ex have a nasty confrontation. On her way home to Honolulu, the ex sees a headline announcing the scientist's death--now she's on the lam, but she's also unwittingly spreading the deadly rust.