The French Surete and private eye Higgins are after a killer who uses innocent young Americans in a crooked gambling racket, and who sets sail on an ocean liner that also carries inept scoutmaster Freddie Hunter and his troop of boys. Freddie, who's been a "boy scout" too long, has designs on gorgeous Duchess Alexandria. The boys, far better organized than Freddie, are determined to save him from himself. But who will save Freddie from being the killer's next victim?

During World War II, a young boy and girl, living with their respective families in an apartment house that had restrictions against pets, adopt a lost dog and hide it in a vacant apartment, which may have been the only vacant apartment in the United States at the time this movie was being filmed. A burglar breaks in and the apartment is damaged when the dog and crook have a tussle. This blows the dog's cover, but the kids enlist him in the K-9 Corps, and the dog distinguishes himself in the WWII Italian campaign