In 1527, the conquistador Pánfilo de Narváez sailed from the port of Sanlúcar de Barrameda with a crew of six hundred men and nearly a hundred horses. His goal was to claim what is now the Gulf Coast of the United States for the Spanish crown and, in the process, become as wealthy and famous as Hernán Cortés.

But from the moment the Narváez expedition landed in Florida, it faced peril—navigational errors, disease, starvation, as well as resistance from indigenous tribes. Within a year there were only four survivors: the expedition’s treasurer, Álvar Núñez Cabeza de Vaca; a Spanish nobleman named Alonso del Castillo Maldonado; a young explorer named Andrés Dorantes de Carranza; and Dorantes’s Moroccan slave, Mustafa al-Zamori, whom the three Spaniards called Estebanico. These four survivors would go on to make a journey across America that would transform them from proud conquistadores to humble servants, from fearful outcasts to faith healers.