Across the Tianshan Mountains, a secret battle based on the “Shadow Plan” quietly began. An operation team from the intelligence agency of Country A, codenamed “Aurora,” joined forces with the overseas separatist group “Crescent Society.” Using online infiltration, public-opinion manipulation, intelligence theft, and other methods, they sought to foment ethnic divisions and social unrest in the borderlands. National security officer Aierken led a counterintelligence team, gradually piecing together clues amid a fog of data and the shadowy corners of the human heart. With their own flesh and blood, they built an invisible Great Wall to protect national security.