In this postapocalyptic fantasy, a sea of sand swallows everything but the past.

In an endless sea of sand drifts the Mud Whale, a floating island city of clay and magic. In its chambers a small community clings to survival, cut off from its own history by the shadows of the past.

The promised land of Amonlogia has turned out to be a nightmare for the people of the Mud Whale. Suou and the Unmarked are being held hostage, and in order to save them, Ouni and Chakuro agree to serve the duke as soldiers. Orca's forces and an inevitable bloody battle draw ever closer, but the duke has a far darker mission in mind for Ouni-one that will rock the very foundations of Amonlogia!