Esper & Starn are twin boys who live in a grim world that has been almost laid waste by massive volcanic explosions. Very little grows in Orchard, which used to be a fruit-growing area, but with the death of insects & birds, pollination of the fruit trees is a tedious & precarious undertaking. When the boys discover an intriguing old manuscript in a locked room in their apartment, which tells of gold on one of the forbidden islands the people can see from the coastline, they determine to go on gold-hunt. They manage to construct a glider that takes them far from their home territory, & so begins a whole new adventure for the boys, as they travel from island to island in search of gold. Their adventures are many & they come close to death. They do in the end, find the gold
- but it is nothing like what they expected.