In 16th century China, a Ming army pursues a dangerous mission as they assault a fortress held by the wokou, a pirate faction that raids the coast. The Ming force is commanded by General Yu Dayou, Sammo Hung Kam-Bo. The siege ends in heavy Ming casualties, and the fortress holds. It is revealed that the wokou are a composite force: Japanese ronin, disgruntled Han Chinese soldiers, and a cadre of samurai under Commander Kumasawa, who are working to free a Chinese nobleman who has funded the daimyo.
After another failed assault, a new Ming commander, General Qi Jiguang, arrives to rally the people. He begins to recruit hardened villagers to form a new army, a move born of necessity and resolve rather than wealth or status. Qi launches a night raid that disrupts the Japanese fortress, forcing a retreat. Yet his leadership is questioned: he is nearly arrested for failing to capture the target and is even accused of colluding with the enemy, a precarious stance that tests his authority and the loyalty of those around him.
Meanwhile, the Japanese divide into three groups and plan simultaneous strikes. Kumasawa's forces aim at Xinhe and Taizhou at the same time, while the ronin attack Ninghai. Taizhou serves as the provincial capital, and Xinhe houses the families of Qi's soldiers, including Qi's wife, Regina Wan. Commander Kumasawa believes the three-pronged assault will stretch Ming defenses too thin, while his ward, young Lord Imagawa, argues for a single massive blow against Taizhou. The tension between strategic risk and bold ambition threads through every decision, setting the stage for a brutal contest of wills.
Qi learns of the plan and moves to intercept the ronin, defeating them before returning to Taizhou to defend the capital, even though this leaves Xinhe vulnerable. Qi's wife courageously helps rally the soldiers' families to hold Xinhe together through a desperate, improvised defense, turning homes and workshops into makeshift barricades and fueling a stubborn resistance.
At Taizhou, Qi is pushed to the brink, nearly overwhelmed, until Lord Imagawa defies Commander Kumasawa to press the attack with the surviving ronin. Yet last-minute reinforcements arrive, and the Ming forces prevail, forcing the Japanese to retreat to their ships. Qi then hurries back to Xinhe to relieve the city from the invaders, rallying his troops with steady resolve.
Not content with retreating, Qi and his forces strike as the Japanese attempt to load onto their ships. Commander Kumasawa sends Lord Imagawa to safety before engaging Qi in a final duel, which ends with Kumasawa's defeat and his suicide. The film closes with Qi's wife waiting at home for her husband, hopeful for his return, as life in the village settles into a fragile, guarded peace.