Autumn 1941, Shanghai. The Wang Puppet Secret Service Headquarters "No. 76" And the Japanese Special High School Section launched a radio encirclement and suppression campaign in the concession. Su Huaijin, a radio engineer of the "Carrier Pigeon" group of the underground party of the Chinese Communist Party, lurks as a technical consultant for the Japanese and puppet radio stations, code-named "Razor". When a new detection vehicle was launched in the Special High School, three contact points disappeared overnight. Su Huaijin discovered that the pursuer was actually her Japanese teacher. A silent hunt unfolds between radio waves and blades, between damp alleys and neon lights.
