In the gripping South Korean thriller "I, the Executioner," a seasoned detective and his team must navigate the darkest corners of human nature to apprehend a ruthless serial killer. Led by the hard-boiled and seasoned Detective Seo Do-cheol, the Major Crimes division has long been at the forefront of law enforcement in South Korea, their unwavering dedication to justice driving them to confront the most heinous of crimes. Seo Do-cheol, a grizzled veteran with years of experience under his belt, has spent a lifetime honing his skills and absorbing the pain of his profession. His years of duty have left him a shadow of his former self, his eyes seeing only the depths of human depravity, and his spirit wearied by the endless parade of victims and perpetrators. His team, handpicked for their tenacity and unwavering commitment to justice, has grown to mirror their leader's dark and pragmatic worldview. When a string of brutal and eerily similar murders plagues the nation, Seo and his team are called upon to join forces with rookie cop Park Sun-woo in a desperate bid to track down the killer. Initially, Sun-woo is an intriguing addition to the team, his youth and idealism bringing a welcome contrast to the jaded and weathered Seo. As the investigation unfolds, however, it becomes clear that the duo are worlds apart in their approaches to justice – and that their collaboration may prove more crucial than they ever could have imagined. The serial killer, known only as the "Executioner," has left a trail of bodies across the country, each one bearing the hallmarks of a zealot with a singular obsession. With each new victim, the Executioner leaves behind a baffling array of clues and tantalizing hints, all seemingly calculated to taunt the authorities. But what begins as a cryptic game of cat and mouse gradually exposes a far more sinister purpose – a diabolical plot that targets not only innocent civilians but those tasked with upholding law and order. As Seo and his team delve deeper into the mystery, they face a rapidly escalating threat that pushes them to their limits. Their relentless pursuit of the killer leads them down a labyrinthine path of corruption and deceit, where nothing can be taken at face value. Seo's partnership with Sun-woo becomes increasingly strained, as the more experienced detective struggles to tame his rookie partner's wild ideas and unbridled enthusiasm. Tensions simmer between the two, even as their quest for the Executioner gathers momentum. Throughout the film, Seo's character undergoes a compelling transformation. As he confronts the brutal and unrelenting reality of the Executioner's crimes, the once-toughened veteran detective begins to show signs of wear and tear. The cracks in his armor grow wider, revealing a more vulnerable and wistful side to his personality. His relationships with the people around him – including his team, and especially the younger Sun-woo – become increasingly fraught, reflecting the disorienting and morally tormented state of his own mind. As the climax approaches, Seo's mental scars boil over in a raw display of anguish and desperation. His tragic fall from previously dogmatic morality culminates in a poignant and devastating twist that recontextualizes everything that has unfolded since the beginning of the investigation. "I, the Executioner" offers a haunting portrayal of the delicate line separating justice and vengeance, as the characters hurtle toward their respective tragedies in a desperate bid to stop the executioner – a force both deranged and all too human. Seo Do-cheol's grappling with the darkness he has witnessed forces him into an existential confrontation – one that will define both his own redemption and the warped 'moral' code he has unwittingly employed as his guiding principle. To date, Seo remains ever embroiled in retribution, where every thread in the web of justice continues to grow dislodged from that rational rule that is intrinsic in human nature. When Seo glances over at Park Sun-woo, there is a glimmer of resolve present. This is the glimmer that Park has put within Seo by virtue of their partnership and interactions. Its intensity signals hope that lies in the light he once knew when he started serving.