Prequel to the original series, focusing on Reinhard and his steps up the chain of command in the Galactic Empire. Also focusing on the FPA's Yang Wen-li. A chronicle on how he earned the title "The Hero of El Facile" and his handling of assignments he received after the historic event. Spiral Labyrinth also continues with the background of Reinhard and Kircheis where the first Gaiden left off.
These short stories fill in the background of Yang Wenli prior to the Overture to a New War movie, and continue with the background of Reinhard and Kircheis where Gaiden 1 left off. In these stories, Yang becomes the Hero of El Facile and is given a research investigation of some delicacy, Reinhard's first assignment to a ship at Iserlohn, Reinhard deals with a formal duel among the politics of the nobles, Reinhard's secret mission into Free Planet territory, and the Third Tiamat Battle, wherein Reinhard earns the rank of General at the age of 19.