The traveling Frenchman Foucard impresses the pueblo, even ever-skeptic Don Diego, as magician and pickpocket, then romances Victoria and performs various science-based services to various villagers. Sergeant Mendoza must command the protection of a gold shipment, but as earlier near San Francisco, it is robbed by someone who uses a fireball. Even Zorro was too late and finds Foucard asleep, from a distance. Diego shows Felipe the chemical properties of pyrosulphate solve two of Foucard's mysteries: how the magician 'revived' an apparently dead dove