 Cecile Dubois and Neil Bowman, a British agent, decide to investigate.Eavesdropping, Bowman discovers that a man named Gaiuse Strome is financing the gypsies, and his suspicions on the real identity of Strome centre on a highly wealthy aristocrat, distinguished folklorist and gastronome, Le Grand Duc Charles de Croytor, whose girlfriend Lila Delafont is a friend of Cecile.As they follow the caravan, Bowman and Cecile find that their lives are in danger many times in an effort to uncover the secret the gypsies are so determined to hide, and before long are running for their lives.