Billy is awarded the trophy for doing the most outstanding radio work for the year. Later, he takes Beautia out to eat and is accosted by some thugs. Not realizing they work for Sivana, Billy soon learns of the evil scientist's Ultra-Frequency device, which is so delicately tuned that it can cancel out, by interference, Billy's magic word which turns him into Captain Marvel.; Eve is kidnapped by Grosso, who is under the spell of the Mask, but Spy Smasher is on the spot, saving her and killing the giant kidnapper. However, Alan is ambushed by another of the Mask's men and is taken to the lair of the villain, who discovers Spy Smasher's true identity, then subjects him to the Brainograph. Now an evil menace to democratic society, Spy Smasher turns on the Mask and kills him, but Captain Marvel promises to stop him at all costs.; Hal and handful of Blancas are captured by the army of a surviving Inca city. The queen of the city demands Hal's hand in marriage until her fountain of youth fails her. On returning to the Blanca village, Hal is detained by a Japanese national, demanding to know the location of Maxwell Webb's diamond mine.