Episode 13 of "Hunter with a Scalpel" unfolds with an eerie scene: Eun-seo is confronted with bloodstains splattered across the interior of the van, while Se-eun delights in her birthday presents, oblivious to the impending peril. Just as the joyous moment peaks, Choi Min-guk's unexpected arrival casts a dark shadow over their revelry. In a swift motion, Eun-seo hurls a vial of liquid at Choi's face, seizes Se-eun's hand, and dashes into the dense woods. But Se-eun, haunted by her father's warnings, halts abruptly, despite Eun-seo's urgent pleas.
Elsewhere, Jung-hyun and Se-hyun are raced to the hospital, their conditions critical. The detective team, including Hong Jin-woo, converges at the hospital, and Hong realizes the validity of Jung-hyun's suspicions about Choi Min-guk. Back at the precinct, Chang-jin uncovers a photograph from the Blue Barrel case depicting a man named Go Doo-sam, who turns out to be none other than Choi Min-guk in disguise.
At the NFS, Doctor Cheon eavesdrops on a conversation between Joon-kyung and Kim Myung-kwan regarding Se-hyun. She gathers that Se-hyun is innocent of falsifying reports and rises to her defense. Meanwhile, Choi Min-guk metes out cruel punishment to young Se-eun, forcing her to sit with a bucket over her head as a reprimand for aiding Se-hyun.
In the hospital, Se-hyun stirs from her slumber, and we're relieved to learn that Jung-hyun has also pulled through. Hong Jin-woo stumbles upon CCTV footage showing Se-hyun concealing her notebook in a grocery store. He retrieves it and confronts Se-hyun, yet she remains tight-lipped.
The trio of detectives ventures to Haryong to delve deeper into the Blue Barrel Case. During their journey, they speculate on how Choi Min-guk must have feigned a limp for years. While interrogating Haryong's residents, a woman enlightens them: Choi Min-guk isn't Go Doo-sam but Yoon Jo-kyun. He had a turbulent relationship with Lee Jung-mi, who abandoned their daughter with Jo-kyun and fled with Go Doo-sam.
Hong persists in his attempts to extract information from Se-hyun. She eventually agrees to disclose everything on one condition: he must arrange a press conference. By addressing the media, she explains that Choi Min-guk will come after her, thereby providing them an opportunity to apprehend him.
Jung-hyun awakens in the sterile environment of the hospital, his gaze falling upon a television screen broadcasting a live press conference. Se-hyun strides confidently to the forefront, her form silhouetted against the backdrop of flashing cameras and inquisitive reporters. With a steady voice, she proclaims herself as the daughter of Yoon Jo-kyun, revelations cascading like dominos, implicating both of them as the culprits behind a string of murders dating back to 1999.
