Christoph von Keffenhiller was a prisoner of war on Econia. Before, he was a Captain in the Galactic Empire.

A prequel to Legend of Galactic Heroes, focusing more on Yang Wen-li; how he became the hero of El Facile and how he handled a couple of assignments he received afterward. Spiral Labyrinth also continues with the background of Reinhard and Kircheis where the first Gaiden left off.

A collection of independent short stories taking place prior to the Overture to a New War, some of which are adapted from the novel and some of which are completely original.