The Sui Empire, 607 AD. The land is ruled by a cruel emperor, and the people are in a desperate situation. An experienced mercenary travels with his son. He has fallen into debt and will take on any job—from escort duties to contract killings. Undertaking what at first glance appears to be a routine escort assignment, the man finds himself at the epicenter of palace intrigues and bloody clashes between warrior clans, and now he must confront the spread of man-eating demons.