As the identity of the copycat criminal was revealed, Go Hyun-jung proposed a hostage exchange with Kim Bo-ra. In the episode of SBS's Friday-Saturday drama "Praying Mantis: The Killer's Outing" aired on the 26th, the scene unfolded where Jung Yi-shin (played by Go Hyun-jung) and Cha Soo-yeol (played by Jang Dong-yoon) discovered the identity of the culprit.

Cha Soo-yeol opened up about his past pain to Lee Jung-yeon (Kim Bo-ra) at the beach. He said, "I've been running away since I was young. From my past, from my mother," explaining why he decided to quit the investigation team. Lee Jung-yeon held Cha Soo-yeol's hand and comforted him, saying, "Nothing has changed. You are the person I have watched over and chosen for a long time."

At that moment, Choi Jung-ho (Jo Sung-ha) contacted Cha Soo-yeol to inform him that he had found the doctor's residence. However, when they arrived at the scene, all computers and materials were missing. Choi Jung-ho explained the situation, saying, "It seems he was really in a hurry this time. The scene is a mess," and instructed that Jung Yi-shin should handle the team member issues herself.

While carrying a pregnancy test, Lee Jung-yeon urged Cha Soo-yeol to go, saying, "Go catch the copycat and come pick me up." Kim Na-hee (Lee El), who visited Jung Yi-shin, asked why it had to be her son. Jung Yi-shin replied, "You're just doing your job too. Soo-yeol will bring him. He's as desperate as you are."

Kim Na-hee warned, "It's not that you rejected him because he's your son, but because you hid that fact." Jung Yi-shin mentioned the custody lawsuit and had a private talk with Kim Na-hee. Eventually, Cha Soo-yeol returned to the investigation team. In a call with the culprit, Jung Yi-shin provoked, "You're different from me. You kill because you want to kill."

The culprit angrily hung up, saying, "I'll make you regret not killing me along with my father." Jung Yi-shin asked Cha Soo-yeol, "He said he's happy because of you. How did you meet Jung-yeon?" Cha Soo-yeol realized that Seo Ah-ra (Han Dong-hee) was the culprit. Although the police arrived at the scene first, Seo Ah-ra rammed the police car and kidnapped Lee Jung-yeon.

Jung Yi-shin told Seo Ah-ra, "You're still a kid? What you want is me." Seo Ah-ra proposed exchanging Jung Yi-shin for Lee Jung-yeon. Cha Soo-yeol warned Jung Yi-shin, "You'll die if you go," but Jung Yi-shin declared her decision, saying, "Accept it. Send one and get two."

Jung Yi-shin added, "I'm a death row inmate. Even though I killed the trash who deserved to die, I was judged by the law. But for you..." Some suspected that Jung Yi-shin might have conspired with Seo Ah-ra to use her son to escape. The chief instructed Kim Na-hee to act independently.

Cha Soo-yeol tried to put a bulletproof vest on Jung Yi-shin, saying, "When Jung-yeon returns, we'll track immediately," but Jung Yi-shin refused, saying, "Many people want me dead." Cha Soo-yeol said, "Not me. I'll be nearby, so don't worry," and they set out together.