Episode 7 of "Hunter with a Scalpel" kicks off with a tender moment as Eun-seo bestows upon little Se-eun her very own diary. Se-eun, innocent and uninhibited, fills the entire page with a vibrant, almost menacing, splash of red. In the present, she awakens within the confines of their nostalgic yet eerie old house, her body shrouded in a substance resembling blood, her scalpel mysteriously missing – a discovery that prompts Mr. Choi to meticulously enclose it in a plastic bag for safekeeping.
At the police station, a youthful officer named Seok-woo voices his observation, stating that the portrait depicting the girl in her adulthood bears an uncanny resemblance to Se-hyun. His comment is met with dismissive shrugs from his colleagues. During their case discussion, Seok-woo persists, noting that both the first and third victims had patronized Choi Min-guk’s laundry service. Again, his insight is overlooked, brushed aside as inconsequential due to the laundromat’s high foot traffic.
A poignant flashback unfolds, showing Eun-seo gently guiding Se-eun’s hands as she learns to stitch her doll’s dislodged arm back into place. The serene scene is abruptly interrupted by Mr. Choi’s arrival, instructing Eun-seo to depart and handing Se-eun a blue bucket, urging her to hone her stitching skills further.
Elsewhere, Jung-hyun and Chang-jin pay a visit to the laundromat, engaging in conversation with Mr. Choi. Jung-hyun’s astute eyes detect a noticeable limp in Choi’s gait, to which Choi casually attributes to a past accident. Exploring further, Jung-hyun delves into the laundry room and discovers alocked door, intriguing him further. Additionally, he stumbles upon a black hat, a piece of attire remarkably similar to that worn by the perpetrator.
Meanwhile, Se-hyun ventures to Yongcheon Middle School in search of young Se-eun, to no avail. As Jung-hyun and Chang-jin exit the laundromat, Jung-hyun confides in Chang-jin about his growing suspicions, only to have them brushed aside with indifference. Their paths cross with Se-hyun once more, and Jung-hyun politely requests the toxicology reports on the victims, to which she agrees to forward.
Back in her office, she meticulously excised the mention of pancuronium from the toxicology report. Just as she finished, her father's call interrupted her thoughts. This time, Se-hyun feigned willingness to lend him a hand, hinting at her own potential peril and offering to identify a scapegoat for the murders, whom they could frame instead. Aware of her father's possession of Min-ho's organs, she suggested planting the scapegoat's DNA on them and allowing the police to uncover them naturally. Mr. Choi agreed readily.
At the police station, Jung-hyun couldn't resist revisiting the Blue Barrel case, drawing parallels with the ongoing investigation. His supervisor, Choi Jong-soo, concurred but assigned him to pursue it independently.
That evening, Se-hyun embarked on executing their devised plan. She strolled towards a car that Mr. Choi had meticulously prepared for her, driving to an address he had texted her. Upon entering the house, she gathered strands of hair and a razor blade. A subsequent text from her father instructed her to tidy up any loose ends.
Advancing to the adjacent room, she stumbled upon the house's owner, drenched in blood with an assortment of tools scattered nearby. To her shock, he stirred and, mistaking her for his assailant, lunged at her. In self-defense, Se-hyun retaliated with a dumbbell, ending his life. Her reflection in the mirror, eerily smiling back, haunted her.
Outside, Mr. Choi awaited in a truck alongside Se-eun. He signaled it was time, prompting Se-eun to enter the house and strategically position cameras around its perimeter.
