In picturesque Guzmán, Spain, in a cave dug into a hillside, villagers have gathered for centuries to share stories and secrets. It was here that Michael Paterniti found himself listening to a larger-than-life Spanish cheesemaker spin a tale about an unusual piece of cheese. Reputed to be among the world's finest, it was said to conjure long-lost memories. Then, Ambrosio said, things had gone horribly wrong.