The sixth episode of "Hunter with a Scalpel" commences with the captivating scene of Mr. Choi meticulously trimming the hair of little Se-eun, while nearby, a youthful student named Eun-seo meticulously stitches up a doll. Once Mr. Choi concludes his grooming task, he captures a heartwarming snapshot of the two girls, their innocent smiles frozen in time.
Meanwhile, the atmosphere shifts drastically as the police uncover the third deceased body. Jung-hyun's surprise deepens upon discovering that it was Se-hyun who stumbled upon the grim find. This revelation piques the curiosity and suspicion of his fellow officers, prompting them to interrogate Se-hyun, who deftly navigates their questions with poise. In a gesture of concern for her safety, Jung-hyun presents her with a smartwatch equipped with an emergency call system.
Se-hyun and her team dive into their investigation of the deceased, a woman identified as Mi-young. During their examination, Se-hyun unearths a fragment of a photograph tucked inside the woman's mouth. It depicts a younger Se-hyun alongside Eun-seo, but the portion featuring Eun-seo has been viciously torn away.
Elsewhere, a disgruntled realtor voices his complaints about Se-hyun, believing she has brought an air of misfortune to the neighborhood. In a separate locale, Mr. Choi and his young assistant, Se-eun, embark on a journey to their former abode, an old house steeped in memories.
Back at the forensic lab, Jung-hyun engages in a thought-provoking discussion with Se-hyun, delving into a past case from 1999 known as the Blue Tongue incident. This historical case bore striking similarities, including the use of a specific cleaning agent and a brush in the preparation of the bodies.
Se-hyun astutely observes that the earlier case lacked the presence of thread, prompting Jung-hyun to inquire how she possessed such intimate knowledge. Her casual reply, claiming she had merely read about it, is contradicted by fleeting flashbacks that hint at a deeper, personal connection—one that intertwines her and her father with the mystery of the past.
A nostalgic flashback unveils Eun-seo presenting Se-hyun with a cherished doll during their innocent childhood years. In the present day, Mr. Choi and a little girl find themselves at the same house, where he begins to transform the walls with strokes of paint. Meanwhile, Se-hyun ventures to the old house and discovers its walls rejuvenated in a vibrant pink hue. Inside, an anatomy book lies open, awaiting her return. At this moment, the little girl, clad in a uniform with "Se-eun" meticulously stitched onto it, steps inside. She calls out for her father, and Mr. Choi appears, enveloping Se-hyun in a tender embrace.
Elsewhere, Jung-hyun's boss firmly refuses to authorize his delve into unresolved, ancient cases. Undeterred, Jung-hyun persists in sifting through the files of the enigmatic Blue Barrel case, where the prime suspect was revealed to be Go Doo-sam, Eun-seo’s father. Law enforcement subsequently obtains a composite sketch depicting how the little girl from the photograph might appear as an adult. The woman rendered in the sketch bears a striking resemblance, yet remains eerily familiar.
In a heart-wrenching confrontation, Se-hyun confesses to her father that she had presumed him deceased, hinting at a tragic fall from a mountain in the past. He responds nonchalantly, revealing a chance encounter with a healer. He then notices the subtle alterations to her nose. Se-hyun, driven to extremes, reaches for a knife concealed in her pocket and lunges towards Mr. Choi. Yet, he deftly thwarts her attack. As she renewed her assault, Se-eun, with swift precision, subdues her with a taser.
