The film mainly describes the Ming Dynasty ancestors, Zhu Xi, established a secret military intelligence organization - nine gates (九门), to monitor the government officials and to control the people in the capital. In the middle of the Ming Dynasty, the minister of Military Affairs was attempting to rebel. As being the strongest assassin organization in the capital, nine gates (九门) were ordered to investigate the case. However, this case was intricately rooted, and things far exceeded everyone’s imagination. Even the nine internal forces were deeply involved..