The Nameless Order is based at the Great Wall, which is not just a defensive structure, but a fortress designed to protect humanity from a monstrous species called the Taotie. These savage, rapidly reproducing creatures strike every sixty years and pose a serious threat to humanity. When the Taotie launch a major attack on the Wall, William and Tovar must decide whether to fight alongside the Nameless Order or try to save their lives.
In the final battle, William decides to stay and fight, discovering courage, loyalty and honor in the process. Commander Lin (Jing Tian) and strategist Wang (Andy Lau) lead the effort to stop the Taotie from breaching the wall and advancing toward the capital.
The climax is a risky plan to destroy Queen Taotie, the heart of the swamp. Using powder-based explosives, William and Lin manage to kill the queen by disrupting the invasion. The film ends with a sense of sacrifice and triumph as the survivors reflect on the hard-fought victory
