Hyper Knife (Haipeo Naipeu, 2025) TV Series Review: Terrific Performances Anchor This Mostly Engaging Medical Thriller

South Korea has produced some of the most eccentric serial killers in reality, movies, and shows. Shows like Signal, Mouse, Flower of Evil, etc., have sometimes mirrored real-life serial murder cases and sometimes been completely fictional. “Hyper Knife” (Original title: Haipeo Naipeu), starring Park Eun Bin and Sol Kyung Gu in lead roles, is a fictional medical thriller that places itself as the thesis and antithesis of two warring psychotic surgeons.

Written by Kim Sun-hee and directed by Kim Jung-Hyun, “Hyper Knife” follows two extremely skilled genius neurosurgeons who also happen to be dangerous killers. They kill people, sometimes rather unreasonably, while engaging in a war of words, gestures, and ultimately egos. Highly egotistical and overconfident in their surgical abilities, consistently trying to outwit the other, this mentor-student duo of Choi Deok-hee and Jung Se-ok goes through ups and downs in their relationship to the point of obsession. Their egos result in multiple murders and ultimately in the suspension of Se-ok’s surgeon license.

Because of her incapability of performing legal surgeries, Jung Se-ok gets into the shady world of illegal surgeries, frequently successfully performing brain surgeries deemed impossible by experts. All the while, she runs her pharmacy on the outskirts of the city. Fuelled with revenge, all she wants from life is to make her professor Choi Deok-hee pay for the injustice he meted out to her.

Hyper Knife (Haipeo Naipeu, 2025) — A still from “Hyper Knife” (*Haipeo Naipeu*, 2025)

Deok-hee, who is now rich, successful, and a globally decorated brain surgeon, comes across a video of what seems to be an illegal surgery recording from his friend who works in the police department. He recognizes the work is the product of his smartest student, Se-ok. Subsequently, he tries to chase her into committing to a surgery that he thinks is impossible by any other surgeon in the world. The patient is none other than Deok-hee himself. Regularly on prohibited painkillers, a cancer-stricken Deok-hee wants Se-ok to operate on his tumor and save his life.

Marred by the betrayal of her favorite mentor and the heartbreak of a ruined career, Se-ok refuses to perform the surgery and wishes him to suffer till his last breath. However, Deok-hee hides a secret within him that Se-ok is unaware of. As episodes pass, both the mentor-mentee duo are revealed to be sickeningly obsessive and psychotic, like a tragic and fearful reflection of one another. The duo become murderers out of choice, and their desperate attempts to save one another are to no avail.

“Hyper Knife” begins as a very engaging, equally curious case study of two very similar psychotic individuals and their battle of egos. Eventually, the story becomes a complicated drama that tries to explain Deok-hee and Se-ok’s points of view with regard to their complex relationship instead of their individual psyches. The writing takes a lot of time setting up the duo, their equation, their past and present only to muddle up their relationship with some last minute quick reveals and emotional showdown.

Hyper Knife’s story offers no legitimate peek into the serial killer nature of the leading duo and is only interested in dissecting what their relationship looked like. It doesn’t explore Se-ok’s past or how she exacts her revenge on her mentor who ruined her career unreasonably. By the time the show reaches its finale, the writing runs out of steam, and the reveals turn coldly evocative. The lead characters and their turnarounds are not explored neatly either. For the entire duration of the drama, “Hyper Knife” underlines how Deok-hee’s condition is unsalvageable. But, once it’s time to show the challenging procedure of removing his tumor, the show just randomly ends with a post-credit scene. The post-credit scene not only invalidates Deok-hee’s arrogance, persistence, and stubbornness but also terminates the scope of a follow-up season (which is a good thing, in a way).

Undeniably, the show is strongly anchored by its lead actors, Park Eun-bin and Sol Kyung-gu. A particularly nuanced and charged performance from Park Eun-bin makes it clear that she is a force to reckon with. The actor has always delivered exceptional performances, with the recent one being her act in “Extraordinary Attorney Woo.” But “Hyper Knife” has to be her career’s best performance as she tackles a very understated and tricky character with the ease of a veteran. Her breakdown scene in the finale episode will be talked about for years to come.

Sol Kyung-gu brings his years of experience to the table and brings a very complicated character to life. His equation with Park Eun-bin is particularly fantastic, and so is his understated obsessive and psychotic side in the show. The rest of the cast makes a solid mark even with less-developed character arcs.

Beak Eun-woo’s score for “Hyper Knife” is the third main character that entirely steals the show. The score fits the mood of the series, thrills, and chills, and raises the dramatic quotient of the finale episode exceptionally well. The show also flaunts praiseworthy production design and camera-work. To be concise, “Hyper Knife” sets up for a tightly packed, engaging, and thrilling surgical thriller but ends its run as a partially engaging medical drama that explores the duality of a mentor and his mentee as two peas in a pod.