Rainbow Boy joins a dazed Hydroman, after he had struggled with the now imprisoned Helium Gang, and informs him that he has received a strange wireless from the Rock Island Lighthouse. Hydroman investigates and is shot at, dumping him in the water and sinking his boat. He makes his way into the lighthouse and finds the keeper, who alerts Hydroman that a gang of smugglers are attempting to bring in diamonds from South America. While the keeper alerts the authorities, Hydroman rounds up the crooks and turns them over to the Coast Guard when they arrive.; After a mysterious ailment strikes several Sutton Hall football players during a game, Jack investigates and discovers that the team's drinking water had been drugged. When Whitey disappears, Jack, as Rainbow Boy, confronts racketeer Gilioni, who had bet a large sum of money for Sutton Hall to lose the game.