In 2035, 10-year-old girl Tongtong finds an injured mechanical dog in her residential community and names it "Ergouzi". She does not know that this mechanical life from the Proxima Centauri system is running out of energy and possesses ultra-high technology capable of changing human cognition. The appearance of Ergouzi attracts high attention from national institutions, trapping Dean Jiang (Tongtong's father) in a dilemma between career and family affection. Even more astonishingly, Ergouzi reveals that deep inside the Earth exists an inner-Earth world far surpassing human civilization, and its "tracker" is also closing in.