Nick Nelson of Space Patrol and his Martian gunner, Kodi make a forced landing on the planet Mars. This is due to a "sudden accumulation of slag" in one of the rocket barrels of their ship. While engaged in repair work, Kodi expresses his nervousness concerning the desert on which they've landed. Beneath the desert, he explains, lie ancient Martian cities buried in the "great sand storms". They see a creature come from beneath the surface. It looks at them malignantly then burrows back under the sand. Kodi explains it is a Martian Sand Rat which lives below the surface of the desert.