Time is A.D. 927, when Georan invaders have conquered the ancient Korean capital of Balhae and set up a new country, Dongran Guk. The leaders of Balhae desperately need a royal figure to reunite their nation. They find a prince, the previously exiled Dae Jeong Hyeon, who's hiding out under the name So Sam. The leaders dispatch a peerless swordswoman, Yeon So Ha, to protect So Sam before Georan's Killer Blade Army, commanded by Gun Hwa Pyeong, find him first. Initially, he sends his deputy, Mae Yeong Ok, to handle the situation: She wants to become the greatest swordswoman of the age and knows she must first kill Yeon.
On the eve of the founding of the Joseon Dynasty, a delegation of Chinese envoys is transporting the Emperor’s State Seal only to have it swallowed by a whale mid-journey. The substantial reward announced for its return motivates Jang Sa Jung and his mountain men to hunt down the whale. Soon enough he clashes with Yeo Wol, the female pirate captain, putting them on course for an uncharted adventure.
