Sometime in 1737, a Catholic priest climbed into a canoe to save his parishioners’ souls. The cleric in question, Bernardino Pablo López de Escovedo, was a humble vicario—a parish priest’s assistant—working in a parish called Xaltocan, north of Mexico City. Xaltocan’s head priest had fallen ill and abandoned his post, leaving López de Escovedo to handle the parish on his own.