Cuffy's aunt, a relative hitherto unknown to either the lad or the Foreign Legion staff, arrives with documents appointing her Cuffy's guardian in place of Captain Gallant. Gallant is upset, but bows to the inevitable; Cuffy, on the other hand, decides to run away from the fort rather than live with his aunt in the United States.
Manuel Gonzales, a private who needs money to get married, is accused of stealing the legionnaire's pay envelopes. Neither Franca, Gonzales' fiancée, nor Captain Gallant believes the soldier was involved in the robbery even though the soldier appears to have carried out his threat to desert. While Gallant searches for Gonzales, Cuffy and Fuzzy organize a rodeo to raise money for Manuel and Franca's wedding.
On an expedition across the desert, the unit is surrounded by hostile tribesmen. Capt. Gallant and the company's doctor agree to be the tribesmen's hostages in order to guarantee the safety of their fellow Legionnaires.