The story takes place in the early years of the Republic of China. The Huo family and the Zhao family are the two giants in the martial arts world today. They have been fighting over who is the authentic secret boxer. Huo Yuanjia is the fourth son of the Huo family. People are not optimistic about him because he has been frail and sick since he was a child, and they are not prepared to teach him martial arts. However, Huo Yuanjia, who is extremely perceptive, actually realized the Mizong Fist on his own. On the day when the two families agreed to compete, He used the Mizong Fist and defeated his opponent Cheng Tianxiao. Unexpectedly, Cheng Tianxiao suffered a huge blow and passed away. His apprentice Chen Zhen worshiped Huo Yuanjia as his master. A group of people came to Tianjin. Huo Yuanjia, who was highly skilled in martial arts, quickly attracted the attention of the Japanese and was hunted down. They could only take Qiannan to flee to Beijing and set up the Jingwu Sect.
During the war between the Song and Liao dynasties, the Yang family served loyally and bravely to defend the Song dynasty. Under Emperor Renzong, General Yang Liu Lang is trapped in a Liao war formation led by strategist Yelü Haonan. His son, Yang Zongbao, journeys to save him and meets female warrior Mu Guiying who helps to rescue Liu Lang. Although Haonan wishes to marry Guiying, she does not return his affections and seeks help from her master to alter her destiny. This leads to a vengeful Haonan scheming against the Yang family. Eventually, Liu Lang and his wife are moved by Guiying's sacrifice and allow Zongbao to marry her. Meanwhile, Xiao Tao Hou ascends to the throne with Haonan's help and continues to invade the Song dynasty. Haonan unexpectedly falls in love with Yang's servant girl, Pai Feng, but ultimately chooses to retreat from their relationship. Xiao's nephew Yelü Zongyuan, who discovers his roots in the Yang family, struggles between his loyalty and love for his kin...
The divine catcher Tong Lin comes to Gubeikou in search of his missing wife. He saves Meikei Chi, Yan Jinwaner, and others from bandits and later stays at Yuelai Inn. When the innkeeper's wife disappears under mysterious circumstances, Tong Lin suspects his wife and discovers a deeper conspiracy involving the imperial guards.
After a long period of peace, the Western Xia dynasty invades the Song dynasty, leading to the deaths of Yang Liu Lang and Yang Zong Bao at the hands of Pang Tai Shi. Mu Guiying attempts to lead the female warriors of the Yang family into battle, but is falsely accused and faces many obstacles, including being separated from Yang Pai Feng, who later encounters an amnesiac Yelü Haonan and develops feelings for him.
Li Yuanhao, the prince of Western Xia, secretly approaches Guiying and others to deceive them and attempts to use their help to seize the throne. In the end, his scheme is exposed, and he is saved by the Bǎihuā Princess. Guiying is appointed as the commander to fight against Western Xia, but Yuanhao kidnaps Pai Feng and forces Haonan to help him kill his father and seize the throne, as well as to fight against the Song army. Guiying vows to eliminate Yuanhao.
Sergeant Xu Dahu broke several major cases, but his independent style led to conflicts with his supervisor, Li Pengfei, and he was transferred. Dahu resigned in frustration but was encouraged by his girlfriend, Ho Yuk-kam, to start a private detective agency. While taking the police officer's exam, Ho Zi-wai became friends with Li Chang-zi, who was frequently praised and promoted. Zi-wai felt unfairly treated and eventually left his job to join Dahu's detective agency. While investigating a kidnapping case, they discovered more secrets and illegal activities involving Pengfei. They used a citizen's arrest empowered under Article 101 of the Criminal Procedure Ordinance to bring the culprit to justice.