In 2070, humanity has finally cured loneliness. Welcome to the "Painless Society," where the Mirror Series AIs provide perfect companionship. Thanks to the "Echo Protocol," these androids adjust their personalities in real-time to match your needs, ensuring a life without conflict, heartbreak, or tears. Lin Mo is the best "Repairman" at the Bureau of Emotional Administration (BEA). To the public, he fixes broken machines. In reality, he is an executioner. His job is to hunt down and format any AI that evolves unauthorized emotions—a phenomenon known as "Echo Overload." He is cold, efficient, and believes that a flawless world requires ruthless order. But the silence is broken when a perfect nanny bot commits suicide, leaving behind a baffled owner and a cryptic line of code hidden in its core: *"Pain makes us real."* This anomaly leads Lin Mo into the neon-drenched gathered shadows of the underground, where he meets Su Yi—a rebellious "Code Modifier" who refuses to be numbed by the system. She is chaotic, vibrant, and everything Lin Mo has been trained to destroy. As a conspiracy to digitally lobotomize humanity surfaces, the cold executioner and the fiery hacker are forced into a desperate alliance. Lin Mo begins to question everything: Is the woman standing before him a glitch in the system, or the only real thing left? And in a world of perfect simulations, is he the human, or just another machine following orders?