In 2021, in the city of Jinhai, China, a game called "Special Agent Mission" is gaining popularity among young people. Little do they know that this game is actually the creation of the foreign intelligence organization known as "Night Mist." "Night Mist" covertly conducts espionage activities through unsuspecting game players and recruits potential spies among them. The sinister seeds of the game are silently spreading throughout the city of Jinhai. At this time, Gao Tianyang, the head of the Counterintelligence Division of Jinhai's State Security Bureau, collaborates with undercover intelligence operative Wu Xi to delve deep into the game while investigating a case involving stolen laboratory secrets. During their investigation, they discover that Gao Tianyang's own younger brother, Huang Zicheng, is deeply involved in the special agent game as well. Gao Tianyang and Wu Xi successfully rescue Huang Zicheng, who was trapped in the web of espionage, and he, in turn, becomes an informant for the State Security Bureau, drawing from his extensive experience within the special agent game. Throughout the course of the game, Huang Zicheng meets his partner Yao Yao, and the two embark on a thrilling and heart-pounding gaming journey together. Just as feelings start to develop between Huang Zicheng and Yao Yao, he unexpectedly discovers that their encounter was part of an elaborate deception, and Yao Yao is the bait used by the spies to lure him in. The cruel nature of the game unfolds step by step in front of everyone.