Episode 2 of The Scarecrow begins with Tae-joo heading to the prison facility, where he confronts Lee Yong-woo, the Kangseng Serial Killer. Tae-joo demands that Yong-woo confess to the crimes, as his DNA was found at the crime scenes. Despite knowing that the statute of limitations for all the cases has already passed, Yong-woo continues to deny the allegations. Tae-joo urges Yong-woo to come clean to redeem the victims' families, but the prisoner remains unyielding. Yong-woo tries to engage in small talk, but Tae-joo dismisses him and leaves, promising to return the following week to try again.
The episode shifts back to 1988, where Tae-joo confronts Si-young and threatens to shoot him as a joke. Si-young mocks him and vows to take the cases back from Tae-joo and Jae-hoo. Tae-joo recalls how Si-young and his friends bullied him as a teenager by pouring urine on his face while he was passed out. He threatens Si-young with a gun, terrifying him. He reminds Si-young of the past, claiming he is simply returning the favor.
That night, Tae-joo returns to the station, where Seong-jin finds him and thanks him for saving his life. Tae-joo sends Seong-jin away and asks him to look after his parents. The next day, Jae-hoo speaks to the media about the serial killer, confirming four victims and announcing a joint investigation between the police and prosecution.
Meanwhile, the prosecutors discuss the case over a meal. Si-young reluctantly takes on one of Jae-hoo's pending cases that are being redistributed. Elsewhere, Hee-jin is pleased to learn that Tae-joo followed her advice to remove Si-young from the case. She tells her brother to be prepared, confident that Tae-joo will catch the culprit soon. At the same time, Si-young congratulates Jae-hoo and tries to discuss the case, but Jae-hoo avoids him to spend time with his son.
Elsewhere, Tae-joo's sister Sun-young, an elementary school teacher, heads home after work and runs into her boyfriend Gi-beom. They go to a restaurant, where they discuss Tae-joo's return to Kangseng. Gi-beom asks Sun-young to marry him so she can live with him. She hesitates, saying she is not ready yet.
That evening, Si-young meets their former classmate Sang-beom for drinks. He mentions Tae-joo's return, which clearly unsettles Sang-beom. Si-young tells him not to worry and suggests he will find Tae-joo's weakness. Back at the station, Tae-joo speaks with the detectives and suggests that the killer may have made a mistake. He instructs them to question women in Kangseng who may have had encounters with the suspect. A female officer mentions a woman who was kidnapped but escaped and refused to file a report.
Tae-joo and Dae-ho pay a visit to her, pressuring her to speak up. She reveals that the killer spared her because she wasn't wearing stockings, describing his hands as soft and delicate. Meanwhile, Gi-beom escorts Sun-young to meet his family at home. His mother urges him to meet Tae-joo to set a wedding date. Despite feeling insecure about his job, Gi-beom is reassured by Sun-young.
Later, Sun-young requests Tae-joo to set a wedding date as her brother. Unsure of what to do, Tae-joo seeks advice from his colleagues, and Man-chun suggests consulting a fortune teller. Elsewhere, Min-ji runs into Gi-beom at the library and breaks down, remembering her friend Jeong-rin. Gi-beom consoles her and helps calm her down.
Back at the investigation, Tae-joo and Dae-ho map the killer's route using the witness description. They plan to lure the killer by sending a female officer along the same route at night. However, the detectives are redirected to control a student protest instead. Tae-joo isn't surprised to learn that this diversion comes from Si-young's orders.
At an elementary school, Si-young encounters Sun-young, but she doesn't recognize him. On his way out, he speaks with her colleague Jeon Kyung-ho and asks about her. Soon, the protest turns violent, and the police begin attacking the students. Hyung-gu beats a student, triggering traumatic memories for Tae-joo. Tae-joo tries to stop him, but Hyung-gu insists he's doing his job. When Hyung-gu chases another student, Tae-joo intervenes after realizing it's Gi-beom.
Si-young becomes upset that Gi-beom escaped, but Tae-joo warns him against interfering with the investigation. Later that night, Tae-joo warns Gi-beom to stay away from protests and threatens to lock him up if he disobeys.
The next day, Tae-joo revisits the plan to lure the killer. A female officer agrees but is injured during the attempt, forcing them to reconsider. Man-chun brings in reporter Ji-won, who volunteers to act as bait. Tae-joo is reluctant but agrees, instructing her to avoid wearing stockings and to watch for a scarecrow.
Meanwhile, Kyung-ho drives Sun-young to the hospital to visit a student. Gi-beom, waiting to pick her up, is shocked to see her leaving with Kyung-ho. At the hospital, Kyung-ho offers to drive her home again. Gi-beom grows concerned when Sun-young doesn't answer his calls.
During the drive, Kyung-ho brings up Sun-young's mother, making her uneasy. She asks to get out, but he refuses and continues talking. Sun-young becomes agitated and tries to force him to stop. The car crashes into a ditch, and when she attempts to escape, Kyung-ho pulls her back and attacks her.
Meanwhile, the killer prepares to strike again and kidnaps a young girl in the fields. He soon notices Ji-won passing by and shifts his focus to her. Tae-joo and Dae-ho search for Ji-won. The killer chases her, leaving the first victim tied near a scarecrow.
The girl struggles to free herself while Ji-won runs and manages to take a photograph of the killer. Tae-joo finds and rescues the first victim, asking Dae-ho for help. He then searches for Ji-won and finds her unconscious in the field.
Tae-joo rushes her to the hospital, where he learns that Sun-young has also been admitted. He goes to check on his sister and finds her unconscious as well. That night, Si-young manipulates Jae-hoo, who is already distressed about his missing son Hyeon-cheol. He takes him to a location where Hyeon-cheol is being held. Si-young claims the boy is a protester and threatens legal consequences under national security laws.
Back at the station, Tae-joo encounters Kyung-ho being escorted out. Kyung-ho talks about Sun-young's mother being a bar hostess. Tae-joo overhears this and attacks him. He is taken into custody, but Man-chun argues with the police chief, asking him to be released. The chief confirms that Si
