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.