Joe Palooka kayos Cardona, but the latter protests that he can beat the champ in his own country - South America. Cardona’s manager, Anton Kindel, persuades Palooka’s manager, Knobby Walsh, to agree to a return bout in South America in the summer, but Knobby doesn’t realize that the South American summer is only four weeks away. When Anne Howe can’t accompany boyfriend Palooka on the S.S. Valora, she secretly becomes a reporter assigned to report on his training aboard ship. Myra Madison and Chick Bennett plot to get $20 counterfeit plates to South America, but the plates are stolen from her hotel room. Other ship passengers are Austin, an investigator posing as a writer, and Professor Lilliquist, on his way to the Museum Nacional. Ship Captain Lance announces that, following a knifing, Austin is dead. He was only wounded and asks Joe and Knobby to help him get the counterfeiters. The Professor asks Joe to deliver an ancient Inca statue to the museum, and during the night the statue is switched for one containing the plates.