In 2048, the city of Mirage becomes the trial site for the Lingyun system, the first real-world application of smart brain technology meant for wide public use. On the day of the system's conference, an accident sparks an emotional entanglement between founders Zhou Tong and Zhao Feibai and their childhood friends Ayigul and Aizmat. To reach his own goals, Zhou Tong seals the minds of the other three inside the Lingyun system's sandbox space. The move accidentally switches on Lucoco, the system's original intelligent AI. Everything ties back to an "imprint" game the four remember from years ago, as an intelligence crisis coded "human heart fetters" plays out across the real and virtual worlds.