The story mainly tells that Gao Tianyang (Han Geng), the chief of the reconnaissance section of the National Security Bureau of Jinhai City, discovered that the foreign intelligence organization "Night Fog" developed a game called "Agent Mission". They used players to secretly carry out espionage activities under unknown circumstances, and even Huang Zicheng (Wei Daxun), the younger brother who grew up with Gao Tianyang, was deeply involved in the agent game. During the game, Huang Zicheng met his partner Yao Yao (Li Yitong), and the two spent a game journey together. Just as Huang Zicheng's feelings gradually grew, he accidentally discovered that his encounter with Yao Yao might not be a coincidence... The cruelty of the game appeared step by step in front of everyone. Gao Tianyang and Wu Xi (Zhou Fang), an intelligence officer lurking in the agent game, cooperated with each other to uncover the secrets of the spy organization. How can gamers who have strayed into the maze get out? How will the national security personnel gradually crush the conspiracy of the spy organization?