Children of the Whales, Vol. 11 by Abi Umeda

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.

Orca and his imperial troops have arrived at Amonlogia, and Chakuro and the other Marked hope to use the chaos as cover for a rescue operation. But as they attempt to breach the castle to save Suou and the Ummarked, Orca sets out on a diabolical mission of his own. Can Lykos keep her brother from causing more harm, even if it means killing him?