The drama tells the story of a policewoman, Lin Qiang, who is mistakenly treated as a drug dealer, and the police force smoothly arranges for Lin Qiang to hide her identity and start to carry out the undercover mission to collect evidence of the drug dealer's crimes.

The first episode of the drama: in the amusement park, "Wang Qian" in the deal with drug dealers Cong Zi was blackmailed, in order to retrieve the cash and Cong Zi had a fierce battle, the drug lord Qiu Hu appeared behind the scenes with a gun. At the crime scene, SWAT team member Cheng Jingsong calmly handles a hostage-taking incident and successfully completes the mission. Lin Qiang wants to ask Cheng Jingsong to help him to get through the exam, but he refuses.

Unsurprisingly, Lin Qiang, who had been dealt with by Cao Yongming for committing a crime, was brushed aside by Cao Yongming in this police force selection. Based on the information on drug dealers provided by Vice Captain Cao Yongming, Captain Cheng Ji thought of overseas drug lord Ma Hongtao, and immediately called an undercover agent codenamed "Iron Sword" far away from Hongwa to ask for news about Ma Hongtao's underboss Qiu Hu.

Episode 2：

Cao Yongming designed to interrogate Wang Shanshan, unaware of the plan, Wang Shanshan impulsively said the suspect called Congzi is Qiu Hu's subordinates, accounting for her half-sister Wang Qian to Qiu Hu to buy drugs.

Lin Qiang, based on the address information of the massage parlor on the lighter left by Tsung Tzu at the scene, disguised as a masseuse to listen to the information of the deal between Tsung Tzu and Wang Qian. With the cooperation of De, Lin Qiang used the blindfold to make Satoko mistake her for Wang Qian, who came to recognize her face, and used a trick to trick Wang Qian to the bar and get the cell phone she used to contact Satoko.