In December 1949, Shanghai was liberated. Chen Gongpeng, the spy chief lurking in Shanghai, formed a huge underground enemy organization "Guangfu Society" in order to undermine Shanghai's public security and financial and market order.

At that time, it was only a few months after Shanghai was liberated, and the RMB had just been put on the market. Since the broad masses of the people had been devastated by the Kuomintang’s gold yuan coupons, they did not believe in the credit of the RMB and wanted to promote the circulation and use of the RMB. Silver dollars and counterfeit banknotes are the biggest enemies.

After Chen Gongpeng came to Shanghai, he was sensitively aware that this was an available opportunity. Through his connections with the former military commander in Shanghai, he won over a large number of big speculators in old Shanghai and manipulated the black market transactions of silver coins. These people bought low and sold high, and within a few days the price of the silver dollar skyrocketed from 600 yuan to 2,800 yuan, causing market chaos and skyrocketing prices. On the other hand, Chen Gongpeng led his agents and gang members to massively counterfeit RMB and put it on the market, which made the already chaotic market even worse. In the eyes of the general public, RMB almost became a replica of gold yuan coupons. The market is in chaos, prices are changing three times a day, and the daily life of the broad masses of people cannot be guaranteed. Especially the working people at the lower class are deprived of food and clothing. The situation can be said to be extremely critical. In order to respond to the critical situation and crush the sabotage activities of the "Guangfu Society", the Shanghai Municipal Military Control Commission ordered the Public Security Management Committee and the underground party to do everything possible to resolutely crush the enemy's conspiracy, restore Shanghai's financial and market order as soon as possible, and ensure the daily life of the people. Life. After receiving the order, the Governance Committee and the Working Committee quickly established the "Tieliu Action Group", headed by Gu Yunxiao, director of the Public Security Management Committee; Zhang Qiao, the deputy director and an old underground party member, served as the team leader. In view of Yan Shuangying's rich experience in fighting against enemies, In order to gain experience in the struggle, Zhang Qiao specially transferred him from Chongqing to Shanghai and used his abilities to penetrate into the enemy's interior.

The two agreed that only Zhang Qiao knew the identity of Yan Shuangying, that is, a single line of contact. Zhang Qiao would be responsible for using our party's connections in the gang to make Yan Shuangying's identity a secret after liberation. The apprentice of Jin Jiuling, a youth gang leader who has fled to Hong Kong. As a result, Yan Shuangying, a scout from the Fourth Field, transformed into the eldest brother of the Youth Gang who escaped from prison. Zhang Qiao forged all the legal documents that led to Yan Shuangying's imprisonment, and the rest was handed over to Yan Shuangying... Yan Shuang Ying took off his military uniform and mingled in dance halls and casinos. He soon conquered the nearby Youth Gang juniors with his strong martial arts. He then started to compete for the small metropolitan dance hall controlled by the Guangfu Society, openly going to war with Chen Gongpeng, and almost After a vicious fight, Chen Gongpeng and his men became afraid of him, and took the initiative to negotiate with him and asked Yan Shuangying to join the Guangfu Society. In this way, Yan Shuangying became the vice president of the Guangfu Society as the eldest brother of the Qing Gang. However, the matter was not over yet. The cunning Chen Gongpeng's tests on Yan Shuangying came one after another. First, he handed over the wavelength and frequency band of the underground radio station used by the underground mold factory to Yan Shuangying, and secretly observed Yan Shuangying's reaction. Sure enough, Yan Shuangying was overjoyed and handed the wavelength and frequency band to the team leader Zhang Qiao. Not long after, Zhang Qiao found the location of the underground mold factory. Just after the arrest operation started, the alert Yan Shuangying suddenly discovered that, This was Chen Gongpeng's trap. At the critical moment, he managed to notify Zhang Qiao and canceled the operation at the last moment.

After many trials, Chen Gongpeng finally completely trusted Yan Shuangying. However, at this moment, something unexpected happened. Due to the betrayal of a traitor in the Tieliu group, Zhang Qiao was on his way back from Nanjing. , fell into the hands of the enemy, Chen Gongpeng handed him over to Yan Shuangying...

At the critical moment, Zhang Qiao pounced on Yan Shuangying, pulled out his pistol, pointed it at himself and pulled the trigger ···

Facing his old superiors and old friends, Yan Shuangying wanted to cry but had no tears. He swore that he would pay the enemy with blood! In the end, with his superhuman wisdom, he dug out the traitor, found out the list of silver dollar speculators, and cooperated with the organization to uncover the counterfeit banknote printing factory in one fell swoop, completely smashing the enemy's conspiracy and catching all the lurking enemy agents headed by Chen Gongpeng.