In the movie, the Yang family is a well-respected clan of warriors who are fiercely loyal to the Song dynasty. However, when a government official named Pan Mei conspires with the Mongols to overthrow the Song dynasty, he sees the Yangs as a threat and seeks to eliminate them.
The Yangs are initially caught off guard by the attack and suffer heavy casualties. The 5th and 6th brothers, who were not present during the initial assault, vow to avenge their family and take up the fight against the invaders.
Meanwhile, Fu Sheng, the second brother, is devastated by the loss of his family and becomes mentally unstable. He wanders the countryside, haunted by visions of his deceased loved ones and unable to cope with his grief.
The 5th and 6th brothers seek refuge in a Buddhist temple, where they train in the art of pole fighting and plot their revenge against Pan Mei and the Mongols. They are joined by a group of loyal followers, including their sister, who disguises herself as a male warrior to aid in their cause.
The final battle between the Yangs and the Mongols is a brutal and bloody affair, with both sides suffering heavy losses. In the end, the Yangs emerge victorious, but at a great cost. The surviving brothers and their followers realize that their fight was not just about vengeance, but also about preserving their family's honor and defending the Song dynasty from its enemies.