Two years after Ying leaves the Engineer's Guild and the ghost of her father's unjust death behind, life seems to regain a semblance of normalcy. But the winds of unrest continue to stir within the Nine Isles, and the aftermath of a horrific pirate attack by the mysterious Blood Phoenix fleet forces Ying back into the tense political world of the new High Commander, Ye-yang. And soon, Ying, Ye-yang and her former friends from the guild must work together to find a way to outsmart the cunning pirates who terrorise the straits-and the elusive mastermind who's controlling them.

Meanwhile, Ying's sister, Nian, now lives in the capital, awaiting the day she will finally marry the High Commander. While her relationship with Ye-yang remains distant, she finds company in her friendship with the fourteenth prince, Ye-kan, and discovers her unexpected affinity for governance and strategy. But the capital is more dangerous than she expects, and when a dark conspiracy arises, Nian and Ye-kan must unravel the mystery in time to prevent the High Command from collapsing from within.

New dangers arise at every moment, threatening to tear the Nine Isles apart. In order to sail through this storm, Ying and her loved ones must make difficult choices amidst terrible betrayals. With the world on the brink of destruction, will they find a way to defeat their enemies and survive? And will it be worth the cost?