At the end of the Song Dynasty, Mongolia invaded from the north. The young boy Liang Wenjing and his father Liang Tiande avoided Mongolian conscription by entering Sichuan province. On their way, they encountered the royal supervisor, Prince of Huai'an, who was assassinated. Bai Pu, a strategist for the Prince's household, noticed that Liang Wenjing resembled the Prince and decided to replace him with Liang Wenjing. However, Liang Wenjing escaped on the night he was supposed to pretend to be the Prince. He then met a Mongolian girl named Xiao Yuling and a poor scholar Gongyang Yu, who taught Liang Wenjing the "Three Talents Return to Unity Palm" technique to counter Xiao Yuling's Black Water martial arts skills. Unexpectedly, after a series of events, Liang Wenjing and Xiao Yuling fell in love. They also discovered that Xiao Yuling's senior brother Xiao Leng was the assassin who killed the Prince of Huai'an. Later, Xiao Leng came to kill Liang Wenjing but was stopped by Xiao Yuling's plan.