Inside a vast Dyson sphere, a young avian hunter named Wind lives under the watchful eye of the Protector, an ancient machine sworn to keep the world safe by eliminating all outside threats. "Demons," it calls them. Creatures from space: "The Great Below" far beneath their feet. When a fiery alien vessel crash-lands, and its passengers parachute down nearby, Wind's choice to rescue them becomes a fight for survival... and the Protector is not far behind.