In the ancient Korean kingdom of Goguryeo, a ruthless king reigns and the good princes and princesses of the nation live with the constant fear of death. After the forced suicide of his elder brother Haemyung, the previous heir to the throne, the new Crown Prince Muhyul resolves to save his siblings by doing everything in his power to focus his father's wrath onto himself. One night, his youngest brother Prince Yeojin mysteriously disappears and Muhyul must ride out alone into the desolate storm to find him. Little does the new Crown Prince know that there's far more to the disappearance of Yeojin than his father's madness. The forces of Heaven and Hell are moving and Goguryeo lies at the center of their plans.