Fang Han is in a sorrow when knowing his girlfriend, an undercover agent named Luo Fei, is killed in the line of duty. Moreover, the team that Fang Han works for proves to be unsuccessful in putting a stop to criminals engaged in gun smuggling and drug dealing. They suffer heavy casualties and the criminal mastermind escapes. Under the behest of the police chief, Fang Han decides to finish the mission that his late girlfriend started. He goes undercover to put a stop to the drug ring and ultimately bring Luo Fei's killer to justice. ...

Ma Tianming, a poor man from a bad family background, is framed for a tragic family murder and through a series of accidents, he takes on the identity of a doctor who just returned from overseas, Cai Likun, and hides in the Hengshan Hospital. Zhu Tiande, a businessman, is in possession of a large amount of secret bribery money, but he falls into a coma while hiding from the enemy and was hospitalized at Hengshan Hospital. The KMT agents, the Japanese military and the Shanghai youth gang are all eyeing on this huge sum of money in his possession. Cai Likun, who is also admitted to Hengshan Hospital because of his injuries, is the special agent sent by the Soviet Union to meet Zhu Tiande. He asks Ma Tianming to upkeep his fake identity, and the two of them form an alliance to fight against the evil forces. In the dangerous battle of wits and bravery, Ma Tianming, who was originally bent on money, is impressed by the noble spirit of the revolutionary Cai Likun and grows into a revolutionary fighter who understands national justice and finally overcomes the villains and completes the task assigned by the organization, while also clearing his own name....