The Public Security Bureau intercept a telegram notifying foreign agents to retrieve the "110 secret". Shi Yan, head of the Reconnaissance Section, starts a campaign of counter-espionage, but one of his agents is soon killed on board a train.
Three Black Triangles (1977) is currently not available on any services.
Lei Ming , Ling Yuan , Liu Jia , Ping Zhang , Bi Jianchang , Qin Wen
Chen Fangqian, Liu Chunlin
Beijing Film Studio
