The old con man Zhai Guanyi (played by Ruco Chan), who has been in the underworld for many years, is summoned by his master Szeto Sing (played by Poon Chi Man) to watch the battle with six of his fellow disciples, Ho Ching-wah (played by Lam Ha Wai), Wu Pak-yi (played by Chan Shan Chung), Ding Quan (played by Lam Chi Shan), Li Heng (played by Xu Rong), Wu Shifeng (played by Wong Cheung-hsing) and Su Lifen (played by Chiu Hei Lo), to witness the battle of the century between Szeto Sing and the boss of Jun Sheng Entertainment City, the gambling king Fok Chun-sheng (played by Shan Liwen). This battle taught Guanyi a lesson: "The ruthless is the winner"! After the battle with the gambling king, the "Seven Heroes of the Thousand Doors" went to the entertainment city to take up different positions and find the traitor for the crisis-ridden entertainment city. Guanyi and Zhenghua were forced to spend every day together because of this mission. The two were originally lovers and almost got married, but Guanyi betrayed Zhenghua to win the gambling king championship, and since then the two have nothing to do with each other. Among the seven, Kwun-yi and Pak-yi, who is proficient in magic, have worked together for many years and have a tacit understanding. Kwun-yi and his team narrowed the scope of their investigation and investigated Chun-sheng's assistant, Lam Lei (played by Wong Chi-hung), who is as close as a brother to Chun-sheng, and Chun-sheng's lover and confidant, Yau Yuet-wah (played by Chan Sau-chu). After a lot of clues, everyone suddenly discovered another clue related to Chun-sheng and Lam Lei. It turns out that the entertainment city was established by Chun-sheng, Lam Lei and Chiang Tin-lung (played by Ng Tai-yung). Tin-lung is the eldest of the three, but he has been missing for many years and his life or death is unknown. Chun-sheng became the owner of the entertainment city because of Tin-lung's disappearance.