At the end of the Joseon Dynasty, a military unit of elite (students of the Clear Wind Shining Moon sword school) is created to ensure the peace and the safety of the country. In its center, the two best swordsmen, Ji-hwan and Gyu-yup, are also two inseparable friends. But a political plot forces Gyu-yup to not only kill his fencing master, but also Ji-hwan. Five years later, Gyu-hup became a cold and cruel soldier called the human butcher. It inquires then into a series of political assassinations aiming at the protagonists of the plot. The discovery of a sword carrying the seal of the old unit of elite of Gyu-yup confirms the assumption that Ji-hwan is back.