A wagon train travelling from Independence, Missouri to Santa Fe means trouble for Alfredo Dupray, his authority from Spain will end with the arrival of a Mexican Governor. He plots to solve this by intercepting a trade agreement, to be negotiated by Clark Stuart on the wagon train, and disrupt US-Mexican relations.
Repeated attacks are thwarted, however, by the appearance of a mysterious Rider on a Painted Stallion who issues warnings with her whistling arrows. With her help Clark Stuart, along with historical characters, Kit Carson, Jim Bowie and Davy Crockett work to defeat Dupray. Eventually, they assist the arrival of the US Cavalry and the treaty is signed, leaving Stuart and the Rider to ride away together.
Repeated attacks are thwarted, however, by the appearance of a mysterious Rider on a Painted Stallion who issues warnings with her whistling arrows. With her help Clark Stuart, along with historical characters, Kit Carson, Jim Bowie and Davy Crockett work to defeat Dupray. Eventually, they assist the arrival of the US Cavalry and the treaty is signed, leaving Stuart and the Rider to ride away together.