15 years ago, A-Lung's (Sam Lee) father died in a car accident because his mother, Shan Jie (Lu Shan), was addicted to gambling and borrowed money from loan sharks to pay off debts. Therefore, A-Lung and his sister, Wen Wen (Ng Lixuan) hated their mother very much. However, for Wen Wen's livelihood and to protect his family, A-Lung joined the loan shark group of Tin Sin (Lam Suet) and began his loan shark career. A-Lung encouraged Wen Wen to join the police force, but because of A-Lung's professional background, Wen Wen was under pressure, which led to the breakdown of the relationship between the siblings, and finally Wen Wen left the police academy. One day, a special operation team claiming to be specialized in eradicating loan sharks found A-Lung and asked him to collect evidence of Tin Sin's crimes as an undercover agent in order to eliminate loan sharking activities. While A-Lung was working hard to search for evidence of Tin Sin's crimes, Wen Wen also joined Tin Sin's group and approached Hei Gou (Cheung Siu Fai) who was making things difficult for him in order to compete for the position. Black Dog is the adopted son of the gods and has always been valued by the gods. However, since A Long joined, he felt that his position was no longer secure and he has always regarded A Long as his enemy. He and the gods did not know that Wen was Long's sister and that he had fallen in love with Wen. Black Dog already had a girl named Xin (Irene Wan) by his side. Her father was a debtor. In order to save her father and take care of her mother, Xin had to get close to Black Dog. However, the appearance of Wen also made Xin feel that her position was threatened. Xin felt that Wen's appearance was by no means accidental, so she doubted her true identity. She advised Black Dog not to trust her too much, but Black Dog did not believe it. In order to find evidence, Black Dog set a trap to test Wen. Unexpectedly, Wen really fell into the trap. At the critical moment, Long, who knew that his sister was in danger, appeared.