In the new Beijing of 2045, holographic advertisements and neon lights cannot drown out the remaining courtyard communities in the Second Ring Road. Qi Lin brought his adoptive son Xiaodao, who was a mechanical genius, to make a living by modifying antique appliances, until he bumped into Huo Xiaoman who had climbed over the wall on a rainy night - the chip behind her neck was flashing a dangerous red light.
The global technology giant "Neuron" is chasing Xiaoman. They need the first-generation neural interface data in her brain. Qi Lin discovered that Xiaoman's chip could resonate with the old circuits in the courtyard, triggering the dusty Cold War computers in the underground air-raid shelters. When the villain's drones surrounded the bricks and gray tiles, the range hood turned into an anti-aircraft cannon, an old radio broadcast an electromagnetic pulse, and Xiao Knife's mechanical dog assembled from toy car parts chewed through the killer's prosthetic eye circuit.
This cyber attack and defense battle among the cornices and brackets finally revealed the truth about the damage to Qilin's robotic arm: the "accident" three years ago was the result of the Neuron Company's attempt to seize the parent-child AI core developed by him. The bronze piles under the courtyard rumbled up to form a Faraday cage that isolated signals, and the ginkgo tree in the corner of the courtyard suddenly bloomed with flowers shaped like data flow - this is the analog firewall left by the first generation of computer experts in the early years of the founding of the People's Republic of China.
