The wicked Mateos bandoleros kidnap the Papago girl, Daana, to resell her as a slave, setting their eyes on an old Spanish medallion possessed by the Indian girl. Tex and Carson intervene, driving out the ruffians and leaving them dismounted in the middle of the desert and then they take the girl back to her father, the Papago sachem, Manuelito. Daanas necklace, according to ancient stories, leads to a fabulous treasure and the rangers follow its trail, discovering that the fabulous riches are by now lost. And when the two gringos return from the expedition, they must face the anger of Mateo and of his vindictive hired ruffians.