On a rainforest island in the western Pacific, ninety-two artificial islands rise from a shallow lagoon. They are built from columns of basalt, stacked log-cabin style, and the largest of them weigh fifty tons. The columns came from a quarry on the other side of the island — twenty-five miles away by sea. The people who built Nan Madol left no writing. Their descendants remember a flying dragon that carried the stones through the air. A sleep walk through the strangest stone city on Earth, and the question that nine hundred years of contact has not answered: how.