Synopsis：In the world, there is a most terrifying poison called Wuyi Poison, which is not only complex in design but can also arbitrarily control life and death. This poison, once lost by the Tang Clan, has suddenly appeared in Rainbow Sun City deep within the desert. The Tang Clan sends its second son, Tang Zhongsheng, to investigate. Meanwhile, the legendary chivalrous hero White-Clothed Marquis, who has long been absent from the martial world, also becomes entangled in this incident. Since everyone arrived at Rainbow Sun City, people have been dying mysteriously one after another. The city guards launch a massive manhunt for the suspect Tang Zhongsheng, while White-Clothed Marquis and the street rogue Liu Chan’er are drawn into the incident and fall under suspicion. Fortunately, Yun Ling of the City Surveillance Bureau believes in them and helps them escape the pursuit. White-Clothed Marquis and his team begin investigating the truth, and a dark past gradually comes to light. It turns out that City Lord Yun and his associates are the "Three Ghosts of Tang Clan" who fled the clan twenty years ago. They escaped to Rainbow Sun City and used a group of children as test subjects to create the terrifying Wuyi Poison Gu, controlling the lives of everyone in the city. To raise the Gu King back then, City Lord Yun sacrificed half of his lifespan. Now, to extend his life, he plans to set up the Five Yin Formation, sacrificing the entire city to summon all the Gu. The lives of everyone in the city hang by a thread. White-Clothed Marquis steps in and breaks City Lord Yun's formation, only to discover that City Lord Yun is merely a pawn. The true mastermind is the great demon Zhuque, who shares a deep and tangled history with White-Clothed Marquis.