The Pan-American Congress erects "The Caldwell Line," like a seagoing Maginot Line, that parallels the entire eastern coast of the western hemisphere. This is in place in order to blockade the landlocked Axis powers, thus crimping their food supply. So now the Axis Secret Police need to do some sabotage, but first Madame La Coquin invites Black X to a fashionable Washington party, so that she can kill him. Batu uses an illusion to make them think Black X is really dead, allowing the Axis to complete their plans to destroy The Caldwell Line.; Jarmanian spies Rudolf Hitz and Olga, working with Public Enemy #1, Scar Pipalle, kidnap a General's son, and try to blackmail him for the gold at Fort Adam in Kentucky. Hugh Hazzard and his Iron Man Bozo the Robot stop them, with the unexpected help of the notorious but patriotic Pipalle, who in the critical moment refuses to betray his country, and gets shot in the back by Hitz, who gets captured alive.; Police are baffled as a safe goes missing after a horrible fire at a local hotel. Kent Thurston suspects arsonists, and investigates as the Invisible Hood. The arson gang wears asbestos suits, but are quickly defeated.; The Voice kidnaps Lola Barnes and demands Sir Sidney trade the Red Star Diamond for her.; Flash and Andy accidentally stumble upon a kidnapping.; Archie turns over a new leaf and decides to be tough.