In 1931 Shantou, the situation is tense due to conflict between the Kuomintang and the Communist Party. At this time, the mysterious traffic station set up by the Communist Party is being targeted by Wang Li Wen. When he unexpectedly reunites with his sworn brother Chen Jia Dong on the streets, they begin to jointly investigate the secrets behind the traffic station. Given the difficulty distinguishing between friend and foe, the two began to re-examine each other's true identity.