Based on Jin Yong's classic wuxia novel, the series follows the life of Yang Guo, an orphan who grows up in a world of martial arts and betrayal. After being sent to the Quanzhen Sect, he escapes and finds refuge with the mysterious and beautiful Xiaolongnü, a master of the Ancient Tomb Sect. As they live together in isolation, their master-disciple relationship evolves into a deep, forbidden romance that challenges the rigid moral codes of the martial arts world. Throughout their journey, the couple faces relentless persecution from society, internal conflicts within various sects, and the looming threat of the Mongol invasion. Yang Guo must navigate his own path to becoming a legendary hero while protecting his love for Xiaolongnü, ultimately proving that their bond is stronger than the prejudices of the world around them.