The seventh episode of "Hyper Knife" kicks off with Se-ok standing frozen in shock as Deok-hee plunges a blade into Min and drags him into a narrow alleyway. Young-joo bursts onto the scene just in time to witness Inspector Yang's arrival, swiftly whisking Se-ok away before her eyes can fall upon Yang. A text message arrives on Se-ok's phone, bearing an address. Upon reaching the designated location, she discovers Min's car keys – a potential escape vehicle for her and Young-joo.
Later, Se-ok dials U-yeong's number, inquisitive about his earlier assertion that Deok-hee's days are numbered. He agrees to forward her the MRI scans he had accessed. Elsewhere, Inspector Yang and his companion discover Min's lifeless body, a grim testament to the violence that unfolded.
Deok-hee retreats to his home, where he finds a package from Alan containing a mere handful of painkillers. Alan apologizes over the phone, explaining his inability to procure more.
Back at her place, Se-ok receives the scans from U-yeong. They tell a vastly different story from the CT scans Deok-hee had shown her, revealing that Deok-hee's condition is far more dire than she had imagined. Young-joo, mindful of the sacrifice he has already made by taking a life for her, urges Se-ok to save Deok-hee.
The medical examiner informs the detectives that the killer deliberately targeted Min's spleen, ensuring internal bleeding – a detail that hints at a medical background, sending a chill down Yang's spine. The police also uncover CCTV footage, capturing Deok-hee from behind as he forces Min into the alley. Seong, one of the officers, alerts Kim Doo-bong to the murder, and his surprise is evident upon learning that the perpetrator is male.
Han Hyeon-ho returns after attending to the cult leader, his expression grave. Se-ok and Young-joo pay him a visit and are horrified to discover bite marks on Hyeon-ho’s hand, inflicted by the cult leader during his care. Se-ok Announce with resolve that she intends to perform surgery on Deok hee She unveils the MRI scans to Hyeon-ho, illustrating how the tumor has encroached upon the arteries, necessitating a highly intricate procedure known as a cerebral artery bypass with vein grafts.
Simultaneously, Deok-hee introduces Alan Kim to his hospital staff, amidst a backdrop of anticipation. Dr. Song mentions an impending surgery, another cerebral artery bypass, sparking curiosity. Alan Kim expresses his enthusiasm about collaborating with Se-ok, reminiscing about a genius physician he once worked with who, despite his brilliance, alienated everyone around him, ultimately leading to his tragic suicide.
Se-ok is then summoned for a visit by Kim Doo-bong, who broaches the sensitive topic of Min’s demise, inquiring about the motive behind a man’s involvement in the assassination. She curtly reminds him that the mission was accomplished, quelling his further inquisitiveness. He then mentions having watched her surgery video, renewing his offer of assistance, a gesture of gratitude should she ever find herself in need.
Inspector Yang invites Deok-hee out for dinner, the atmosphere tense. As Deok-hee arrives, a text notification informs him of Kim Ki-young’s passing. After indulging in a few drinks, Yang bluntly confronts Deok-hee about Min’s murder, revealing that he witnessed Deok-hee on the fateful day. Deok-hee, unperturbed, counters by hinting at his awareness of one of Yang’s own skeletons in the closet, leaving the dinner table charged with unspoken truths and hidden agendas.
Yang returns to the precinct and is handed a higher-resolution copy of the CCTV recording. This time around, his eyes light up as he spots Se-ok lurking in the throng. Later, at Ki-young’s funeral, Deok-hee and Se-ok cross paths, with her demanding an explanation for Kim Myeong-jin's murder. Reluctantly, Deok-hee unburdens himself, revealing that Kim Myeong-jin had designs on recruiting Se-ok for his own hospital. Deok-hee, who had invested so much in nurturing her talent, couldn't bear the thought of losing her to another.
At his residence, Deok-hee confidentially informs Alan of the surgical arrangements he has meticulously made at the hospital. He feigns that Ha U-yeong will assist Alan in the procedure, when in reality, it is Se-ok who will be wielding the scalpel. Elsewhere, Se-ok and Han Hyeon-ho venture into a hospital in search of a suitable operating room. The attending physician, ever obliging to Hyeon-ho, graciously offers them an unoccupied one, stipulating that it must be spotless by 6 am. Meanwhile, Young-joo, patiently awaiting in the vehicle outside, observes another car rolling up. Mrs. Ra steps out, presenting him with a business card before departing.
Inspector Yang subsequently summons Se-ok for interrogation. He unfolds a series of photographs depicting Min's lifeless body, followed by a police report detailing the near-fatal strangulation incident involving Se-ok and Deok-hee during an abortive surgery. Yang attempts to manipulate Se-ok into turning against Deok-hee, yet his efforts prove futile.
A memory lane takes us back to the moment when Se-ok earnestly pleaded with Deok-hee to accept her as his pupil and impart his wisdom. Deok-hee, amused, inquired what he stood to gain in return, to which she replied that she was there solely to learn. Back in the present, Yang accuses Se-ok of indulging in clandestine surgeries. He further asserts that she has become Deok-hee's Achilles' heel and a murderer at his behest. Se-ok dismisses these allegations with a nonchalant denial.
Mrs. Ra visits Deok-hee's office to find him methodically packing his belongings. As he is about to depart, his phone rings. It's Se-ok, informing him that she has secured an operating room and proposing to perform the surgery the following night. Deok-hee, without hesitation, concurs to meet her there.
The duo then heads to the hospital, making their way to the old operating room now gathering dust. Se-ok confronts Deok-hee about his abrupt distancing, inquiring if it was because she had discovered his intent to eliminate Kim Myeong-jin. He confesses, acknowledging his shame in the act.
Se-ok responds by revealing that she is aware of his medical condition and vows to perform the surgery herself. Her motive is clear – she refuses to let him perish. When he wonders if her decision stems from pity, she reaffirms her stance, her voice rising as she commands him to steer clear of trouble until she secures an operating theater.
Mrs. Ra trenchantly points out that Deok-hee continues to deceive Se-ok. In response, Deok-hee concedes that he is betraying Se-ok, yet insists that this is the inevitable course they must take. Mrs. Ra declares that she would have resigned had she been privy to Deok-hee's scheme in the first place. As she prepares to depart, she reveals to Deok-hee that Inspector Yang grilled Se-ok for an arduous three hours.
Suddenly, Inspector Yang receives a phone call that urgently summons him from the police station. He hastily proceeds to Deok-hee's deserted garage, where he discovers Lee Wan-il's lifeless body nestled within a refrigerator. At this grim scene, Deok-hee enters the garage and casts a haunting gaze upon the tragedy. Meanwhile, in the operating room, Se-ok and Hyeon-ho meticulously prepare for Deok-hee's arrival, their anticipation palpable. However, it is not Deok-hee who appears at the end of Hyper Knife Episode 7, but Alan Kim, casting an air of unexpected intrigue into the mix.
