Aderyn's courage and skills are put to the test when she and her friends travel to the Southlands on a quest to repel an invasion of vicious orcs—a quest that requires Aderyn to find and command an army. But in a land where politics can be deadlier than warfare, military strategy soon becomes the least of her concerns.

When threats emerge from unexpected quarters, the team must brave the legendary Ivory Palace, a dungeon whose reputation for horror is matched only by its beauty. With time running out for both her team and the kingdom she's sworn to protect, Aderyn discovers the dangers of the surface world are nothing compared to what lurks within the ocean's depths.