Fernando Lamas guest-stars as a Mexican bandit turned revolutionary who captures and prepares to execute the Cannon Ranch hands to prove his power.

Manolito is jailed by El Caudillo, the Mexican bandit, when Conchita lures the group across the border. Billy Blue Cannon is allowed to escape, and he returns with El Caudillo's old enemy, Don Sebastian, and the entire group, except ranch hand Pedro, then is jailed. Hope for escape fades when El Caudillo prepares to shoot the group before frightened villagers to prove his power and to force them to join his revolution to conquer Mexico.

John Cannon and Billy Blue are captured by Apaches far from home and made to face death from lack of water.

John and Billy force a wounded Indian, Klosen, to lead them toward water but the Apache escapes. Buck and Manolito catch a glimpse of a war party wearing John's and Billy's hats but harsh desert winds make it impossible to track the missing pair. When John and Billy do find water, renegade Chief Soldado ties them to a rock to die of thirst.

An Indian outbreak threatens to erupt when Billy Blue Cannon and an Apache boy fight over a wild horse.

Chatto, son of an Apache chief, first discovers the prized stallion, but fails in his attempt to capture it. When Billy Blue successfully ropes the horse, Chatto becomes infuriated with Cannon and steals it back. Billy Blue retaliates and a feud begins. Chief Natchez approaches John Cannon and warns him of trouble if Chatto loses the horse. The two boys meet and fight while High Chaparral wranglers and Apache braves watch and prepare for battle.

Chio, an Apache half-breed and his renegades, capture Cannon's supply wagons. Just as food and ammunition for High Chaparral runs out, Chio is captured and brought to the ranch. Meanwhile, Manolito discovers Tina Granger near a burned out stage coach in an apparently unrelated incident. Tina, Chio's daughter, helps him to escape, but leaves her father when he vows to plunder the ranch to gain recognition. Feeling a loyalty to the Cannons who treated her well at the High Chaparral, she leads Buck and Manolito to the stolen supplies and joins them in a dash for the ranch pursued by Chio and his men.