Reinhard von Müsel and Siegfried Kircheis take up lodgings in the dormitory of their alma mater for the duration of their investigation of the death of Karl von Reifeisen. During their first night, Reinhard dreams about past events of his life. The next day, Reinhard and Kircheis begin their investigation, first by examining the murder scene and then looking up on the school records of the deceased before ending with an interview with Moritz von Haase, a student sent by the school principal to assist their investigation, about the conduct and personality of the deceased for possible clues that caused his demise. Overall however, their entire day of investigation ended with no headway towards solving the case.
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.
