When a Snail Falls in Love

Ji Bai goes to Myanmar to obtain a pipe that belonged to Ye Zixi's father. Two new female intern police officers are assigned to the Violent Crimes Unit. Yao Meng is strong, confident and the Public Security University pentathlon champion. Xu Xu is small and frail and was assigned the Director and the Psychology Institute to act as a profiler.

The Violent Crimes Unit's first assignment involves a case where cutters marked with the Ye Corporation logo were hidden in a park and children were hurt. Zhang Shiyong, the president of Ye Corp hardware was kidnapped. The ransom money is prepared and taken to the airport for the exchange.

XuXu is taken hostage by Yang Yu but Ji Bai is able to save her. During interrogation of Yang Yu, the kidnapper, Xu Xu determines that he was determined to kill Shiyong anyway. Attempting to convince Ji Bai of her theories, Xu Xu becomes exasperated. Ji Bai demands evidence and not just speculation, instructs her in correct investigative procedures, finds fault with her assumptions and admonishes her.

Zhao Han stands up for Xu Xu but Ji Bai tells him if she doesn’t qualify for her fitness exam in 3 months, both of them will be dismissed from the team. Yao Meng works with Xu Xu to get her into shape. Ye Corp shows a marked decrease in profits causing major concerns. Xu Xu questions Yang Yu and Ye Zixi further because she believes the kidnapping case is more complex than originally thought.

Xu Xu and Yao Meng find conflicting data in the statements while investigating the scene. Ji Bai finds links to human trafficking while watching camera footage. Ye Corp's sensitive information is leaked. Xu Xu discloses that Yao Meng is concerned about Ji Bai's feelings and becomes distressed when she realizes she hurt Yao Meng. Ji Bai thinks she may be teachable. The team is called to the murder of a missing mute girl.

Both Xu Xu and Yao Meng are excited when Ji Bai decides to teach them both. However, Xu Xu must still pass the fitness test. Xu Xu comes to the conclusion that Ye Zixi is involved in the kidnapping scandal. The team raids the hideout of Ma Rongrong’s murderer. They capture him, Chen Yong, and another trafficker, Guan Nam. Yao Meng gets cut while apprehending Guan Nam.

When Ji Bai responds to Zixi’s plea for help, he finds her dead. Xu Xu is called in to assist. Xu Xu's theory that Zixi and Shiyong were having an affair is reinforced. Yao Meng and Zhao Han continue to interrogate the two human trafficking perpetrators. Ye Corp stocks continue to plummet. The Ye family is questioned about the incidents. Ji Bai tries to control his emotions but Xu Xu knows he is under stress.

Shiyong is questioned about his alibi for the time of murder. Phone evidence indicates someone is framing him. Ji Bai finds out that Ye Corp lost 2 billion in their overseas accounts. Ye Qiao is called in for questioning. Xu Xu accompanies Ji Bai when he takes a smoke break. She asks to be in charge of his lighter so she can determine when he reaching his emotional limit.