This compendium summarizes an episodic frontier romance set on the Sonoran llano, where a mixed caravan of Mexican miners and an English mining firm journey to a newly discovered lode at the solitary mesa called the Cerro Perdido (the “Lost Mountain”). Key personae: Pedro Vicente, the gambusino (gold-seeker and guide); Don Estevan Villanueva and his partner Robert Tresillian (owners); Señora Villanueva and her daughter Gertrudes; Robert’s son Henry Tresillian; and a hostile Apache band, the Coyoteros, led first by El Cascabel and later by El Zopilote.

Thirst forces the caravan to divert to the Cerro Perdido, reputed an oasis with a perennial spring and lake. Pedro Vicente’s accurate guidance secures water but also exposes the party: the Coyoteros, expert horsemen and marauders, are in the vicinity. A reconnaissance and then a mad rush for the lake ensue; the wagons are corralled on the mesa and the company retreats up a steep gorge to the mesa top, where the terrain offers a natural, defensible “citadel.”

The Apaches deploy in enfilading lines and, after recognizing the camp as civilian, besiege the summit rather than assault directly. Tension escalates: El Cascabel is shot dead by Pedro Vicente during a moonlit reconnaissance, prompting a vengeful scalp-dance and ceremonial executions of two captured messengers. The Coyoteros occupy the abandoned camp below and destroy or plunder what they can; they also take women and young girls captive from the Horcasitas raid. The beleaguered miners improvise shelter and subsist on limited game and native plants, improvising ropes from mezcal fibre for a daring escape plan.

Henry volunteers for the critical mission to reach Arispe and fetch relief—uniquely able to mount Crusader, his exceptional black horse. He is lowered by saddle down the cliff, finds Crusader, and after a series of desperate encounters and narrow escapes with pursuing Apaches, succeeds in riding to Arispe. His arrival galvanizes Colonel Requeñes and local forces (lancers, howitzers, Romero’s vaqueros), who rapidly march to the Cerro.

A combined force executes an enveloping manoeuvre; the detonation of howitzer shells routs the Coyoteros, who suffer heavy casualties and prisoners. Captives and plunder are recovered; the miners are relieved. The narrative closes with reconstruction and reward: the mine yields a bonanza, Santa Gertrudes grows into a prosperous settlement, and Henry and Gertrudes marry amidst public rejoicing. The story balances frontier peril and improvised engineering, cavalry tactics versus terrain, and the human costs and eventual communal restoration that follow a violent encounter on an isolated mesa.