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?

After defying a gangster in Italy, American jockey Danny Arnold flees race-fixing accusations and escapes to Paris with his son. There, he learns that his old friend has been murdered and finds work through British jockey George Gardner. Despite his son’s hopes, Danny compromises his integrity by winning money on a fixed race.