During a perilous voyage to Alaska, a renegade ship captain and a Nazi agent stop at nothing to steal the Peritron, a powerful ray gun developed by an American scientist for the U.S. war effort. Marine commando Jim Hudson (Milburn Stone), the scientist’s beautiful daughter Ruth (Marjorie Weaver) and their pal Grit (Fuzzy Knight) come face-to-face with an avalanche of natural disasters and man-made horrors – poison gas, polar bears, ship wrecks, plane crashes and of course, murder – in one cliffhanging episode after another!!!