Lee Jong-su, an ambitious young writer, juggles various odd jobs in bustling Seoul until fate leads him to cross paths with Shin Hae-mi, a former neighbor and classmate, during an event where he is making a delivery. Although Jong-su initially struggles to recall her, Hae-mi reveals that she has undergone plastic surgery, which prompts a connection. He gifts her a pink watch he won at the event, and soon after, she shares her plans for a trip to Africa, asking Jong-su to look after her cat, Boil, during her absence. However, Jong-su's life takes a turn when his father, a cattle farmer in Paju, gets embroiled in troubling legal issues, compelling Jong-su to return to the farm.
While tending to Hae-mi's apartment to care for her cat, Jong-su finds himself increasingly drawn to her memory, often indulging in solitude and his own thoughts in her space. He never sees Boil, but assumes the cat is present due to evidence around the apartment. Out of the blue, Hae-mi calls him, revealing that her journey in Africa has taken a dark turn as she was stranded at Nairobi Airport after a nearby bombing. When he meets her upon her return, she introduces him to Ben, a charismatic man she encountered during the crisis, and the trio heads out for a dinner where Hae-mi unveils her desire to vanish from it all.
As the story unfolds at Jong-su's farm, a bond forms over shared moments of joy and cannabis, but the dynamics shift when Hae-mi dances topless in front of the men. Afterward, Ben makes a chilling revelation about his peculiar hobby of burning abandoned greenhouses every couple of months, hinting at the many greenhouses that surround Jong-su's home. When Jong-su expresses concern for Hae-mi's well-being after an unsettling phone call and her abrupt disappearance, his inquisitive nature pushes him to investigate further. He becomes suspicious of Ben and begins to question both Ben's intentions and his connection to Hae-mi.
Jong-su’s hunt leads him to Hae-mi's eerily pristine apartment, devoid of any trace of her cat. He starts shadowing Ben, hoping to uncover the truth, only to confront him about Hae-mi’s whereabouts at a restaurant. Ben, seemingly aloof, denies knowing anything about her and throws Jong-su into a spiral of paranoia and jealousy, suggesting that Jong-su was the only one Hae-mi trusted in her life.
As tensions mount, Jong-su finds himself outside Ben's apartment one day, where he is invited up. To his shock, he discovers a new cat in Ben's possession—one that bears a striking resemblance to Boil. The unsettling discovery of a pink watch, identical to the one he gave Hae-mi, hidden among other women’s jewelry only stirs Jong-su's rage.
Faced with the ultimate betrayal, Jong-su's emotional turmoil peaks during a fateful encounter in the countryside, culminating in a violent confrontation. Overwhelmed by despair, he stabs Ben to death before setting both the body and the car ablaze, erasing any remnants of the life they shared. In a haunting conclusion, he drives off into the night, forever changed by the events that unfolded.
