A clever gang of jewel thieves, possessing underwater speed suits, ray guns and a disguised underwater hideout, lead the Sub-Mariner on a merry chase as he attempts to recover stolen jewels.; Cap and Bucky must face the evil genius of a Japanese man who sends free jigsaw puzzles into American factories, then whose pieces can pick up designs of important American weapons. Once they fall into enemy hands, the designs can be copied to make the actual weapons!; Wealthy Melton Loard is kidnapped, and the kidnappers notify the Whizzer, hoping to draw him into a trap so that they can collect the ransom.