After the zombie wave tore through the city, veteran Qi Zheng was regarded as useless, and even the police dog didn't bother to bark at him. And the data geek Shen Zhiyao uses the city's bulletin board and dispatching system to weave a false illusion of security. Until a heavy rain burst open the city hall filing cabinet, and a fragmented recording automatically played on the conference table - its frequency actually activated the underground air defense system. When everyone knelt down and begged the team leader to seize the way, they discovered that the so-called escape routes were all traps woven by Qi Zheng with silence, and Shen Zhiyao's rules had been quietly rewritten by him using an audio piece that no one could understand.
