レジェンド・オブ・レギオス

Ailen comes back alone from the expedition sent past the aurora walls, and his body does not come back the way it left. Generations earlier a research group called Alchemist built the Subspace Creator System that raised those walls, after Earth's wars over food and fuel made the surface unlivable. Now the same group is pulling at what holds the sheltered world together, and Ailen turns on it. This light novel series is set centuries before Chrome Shelled Regios and its mobile cities.