He told them about vanishing armies in Spain and China, about abandoned Mayan cities, the Roanoke Island colony. And he told them of Joya Verde, a South American jungle settlement that had met a fate similar to Snowfield’s. Joya Verde, which means Green Jewel, was a trading post on the Amazon River, far from civilization. In 1923, six hundred and five people—every man, woman, and child who lived there—vanished from Joya Verde in a single afternoon,
