The world is split between a kingdom of light in the sky and a kingdom of darkness on earth. As the King of Darkness devotes himself to war, monsters ravage his lands. A boy whose village was destroyed by monsters questions the king's rule.

The monstrous Bahl attacks the Kingdom of White, indiscriminately slaughtering all in his path. While Iris rushes to intercept him, the Prince of Darkness begins his training to become king far below in the Kingdom of Black.

In the Kingdom of White, Iris reflects on her duties and the events that led her to become queen. Meanwhile, in the Kingdom of Black, the Prince of Darkness enters a competition to make his position as heir to the throne official.

The prince and Adel travel as envoys to the Kingdom of White. Although they bring an offer of alliance, their nations are still at war, and they are greeted with suspicion and hostility. Can the prince successfully navigate the pitfalls of diplomacy?

Iris agrees to join forces with the King of Darkness to put an end to Bahl and his indiscriminate rampages. The forces of darkness rally to stop Bahl's assault, but can they hold out long enough for the two monarchs to bring him down?

Groza joins the prince and Adel in the Kingdom of White, bringing an offer to extend the peace between the kingdoms. While the two sides work to build their newfound friendship, Groza finds herself irritated by the prince's interest in Iris.