The Japanese special organization code-named "Cobra" lurking in Decheng, which the Decheng Military Telecommunications Office had been monitoring, suddenly changed its password overnight and frequently sent more than a hundred messages to the Japanese Air Force Headquarters. No one could decipher the contents of the messages. The Chief of Military Command in Decheng believed that this was another conspiracy planned by the Japanese army against a new type of weapon to be produced by the military factory, and asked the superior for instructions. The Chongqing Military Command took this matter very seriously and dispatched Bao Zheng, an independent prosecutor from the Ministry of Justice who is good at reasoning, to cooperate with Gong Sunze of the Decheng Military Command Operations Office in the joint investigation.