Yang Tsung-pao is killed while fighting invaders from West Hsia. Members of the Yang clan are infuriated when Wang Ching, a cunning prime minister of the Sung Dynasty who is in control of the army, purposely delays a counter-attack against the invaders. The Yang clan, led by Grandmother She Tai-chun (Lisa Lu), band together to form their own army and leave for the front. Meanwhile Wang Ching (Ching Miao) is passing information to the invaders who, acting on this, plan to ambush the Yangs. A Chinese general, Lu Chao, who escapes from the invaders, warns the Yangs of the ambush, and they make their attack plans. The battle ends with the defeat of the West Hsia troops – and the anger of their king, who blames the defeat on Lu Chao (Yueh Hua). The Yangs are without food and surrounded by the enemy, when the West Hsia king and his troops launch a heavy attack. But the enemy is tricked, and the West Hsia king orders his troops to retreat. Destroying roads and bridges as they go, they are pursued by resourceful Yang warriors, who are later captured. Tricked again, this time by General Lu Chao, the West Hsia king tries to regroup his army, but in vain, for She Tai-chun and her troops cause a great flood and much confusion, during which Lu Chao and his soldiers end the final battle, driving the West Hsia invaders from Chinese soil.