Aiz and her friends make their way to Rivira, the town nestled deep within the Dungeon, only to stumble upon a macabre murder! After determining the culprit must be extremely powerful, everyone seems to think a member of the Loki Familia is the most likely suspect?! Meanwhile, on the surface, Loki embarks on an investigation of her own, delving deep into the sewers to get to the bottom of a mystery that may affect her children's future--as well as that of all Orario...