Deryyn

Three centuries after a thwarted demonic invasion, the Great Orders maintain society as mankind lives within great cities inside mountains called deryyns, protected from the twin suns that keep the world in unending daylight.

The Order of Bazukhar, the Pontifex's elite army, keeps the world safe from the demons' constant attacks, but when the discovery of a long-lost ancient machine threatens everything, a young soldier must confront terrible truths about the world he thought he knew.

The War of the Second Sun is about to begin.