The film is set in 1592. Dr. Dong is a young Chinese man who goes to Korea to further his medical studies. He meets Dr. Son, another young doctor who comes from a medical family serving the emperor, and is stunned immediately by her beauty. As they are heading to Pusan to learn acupuncture, they encounter forty thousand soldiers and five hundred warships from Japan. As the attack at Pusan is swift, Son and Dong rush to Seoul and tell the Emperor of Japan's invasion. The Koreans are no-match for the Japanese army. The Korean King, Sonjo, flees to the north and asks for help from the Ming Emperor in China. After the fall of Seoul, Son and Dong take a short cut to Son's hometown Pyongyang and help the injured refugees. Led by General Konishi, the invaders take Pyongyang with ease and arrest Son's father who refuses to treat the Japanese. In order to ease the heat, Son suggests that for every Japanese soldier she takes care of, five Koreans will have to be released. Formerly as a businessman, Konishi admires Son's personality and makes a deal with her. The Chinese Ruler sends General Li and his army to the strategic River Yalu to break the Japanese. Escaped from Pyongyang, Dong is caught by the Korean Army and is mistaken as a spy for Japan. Luckily, Korean Admiral Yi finds out that Dong is actually a Chinese medical expert and kindly asks Dong to deal with his infected workforce in the factory of the famous Turtle Warships. Teaming up with General Li, Admiral Yi finally defeats the Japanese and recaptures Pyongyang. The war has inflicted heavy death rolls on both sides. With her humanistic ideology, Son is condemned by her countrymen since she does not only take care of the Korean casualties but also the Japanese prisoners of war. Coming back with the Admiral Yi's Navy, Son and Dong meet again. In China, high-ranking officials, who do not support helping the Koreans, seize the opportunity to send Commissioner Shen out to Pyongyang. General Li finally succeeds in destroying the most important warehouse of the Japanese Army in Korea. During the battle, Dong tastes combat for the first time and is saved by Admiral Yi once again. Without adequate supplies, Konishi of Japan is interested in striking a peace pact with Shen. Dong, who knows of Shen's shady history in medicine trading, cannot agree. However, Shen just tells Dong that the deal must be made for the future and the survival of the three countries. Son is among the hostages sent to Japan for the peace pact. In order to free Son, Dong volunteers himself to provide medical treatment for the sickened Toyotomi and improves his health. To reward his effort, Toyotomi allows Dong to meet Son once again in Osaka. Knowing Toyotomi too well, both of them know that they may have no chance to leave Japan for the rest of their lives. Is it really the last meeting between Son and Dong? And will Toyotomi settle with the peace pact or launch his last battle against the Koreans and the Chinese?