Cu Hù takes his newlywed wife Linh on a vacation after her heart transplant. The calm beginning gives way to a creeping unease as Linh starts to experience unexplainable occurrences and dreams of a remote house tucked away in the countryside of Da Lat. The line between waking life and dream becomes blurred as she finds herself drawn back to that place, week after week.
After fifty days, Linh sleepwalks to the grave of Phuong, in an isolated area, where she meets Tam, Phuong’s husband. Tam brings Linh back to his house and informs Linh’s husband that she is with him for the moment. Linh soon realizes that this is the very house she has been dreaming about. Inside, she encounters Phuong’s mother, Bà Lê, and Cu Hu, a longtime friend of Phuong and Tam. As this revelation settles, Linh’s sense of safety frays around the edges.
Linh eventually leaves the guest space and is picked up by her husband, but the echoes of the house linger. A brutal truth emerges: the heart Linh carries is Phuong’s, the daughter of Bà Lê and Tam’s wife. The emotional weight of this fact sends Linh and Tam into a deeper reckoning about debts, loyalties, and the price of living with someone else’s memories inside you. To honor Phuong’s memory, Ms. Le invites both Linh and Tam to stay for Phuong’s 49-day ceremony, a rite that heightens the sense of ritual and the presence of the deceased.
From the moment they decide to stay, the atmosphere grows heavier. Linh experiences more sleepwalking episodes, and Son is haunted as well, as if a hidden force is trying to warn Linh about the truth surrounding their fates. Linh’s connection to the house becomes all-consuming, and she feels that leaving would endanger her life—her heart would give out if she tried to escape.
The emotional pressure peaks when Son confesses a painful truth: he caused the car accident that killed Phuong, but he had been rushing to the hospital at the time. He admits this under the weight of the otherworldly disturbances that have surrounded them. The police, led by [Sau Dung], questions him, and the case seems poised to close, even as the atmosphere grows more unsettled.
As the truth unfolds, Linh reveals a troubling detail: when Son drove away, Phuong was alive but unconscious, not dead. The corpse that the authorities found had been crushed beyond recognition, making identification nearly impossible. Tam confirms that the body is Phuong’s and arranges for a funeral, further complicating the narrative with questions of guilt and cover-up.
Cu Hu discovers a crucial clue: Linh’s blood type is O, which cannot come from Phuong (AB). This medical inconsistency deepens the mystery and pushes the trio toward a dangerous revelation about identity and bloodlines. A funeral table with a picture of Hong appears, hinting at a darker connection between Phuong, Tam, and Hong, a missing piece that demands answers.
Driven by intuition, Linh and Cu Hu head to the night shift at a flower farm where Tam works and press for the truth. Linh insists Tam drive her back to the abandoned house on Ma Ta Hill, where Phuong is discovered to be alive but confined for months, trapped in a desperate bid for survival. Phuong reveals that Hong is Tam’s mistress and that debt and desperation had consumed Tam’s life. Hong had secretly texted Phuong to visit the abandoned house to uncover the truth about Tam’s life, not realizing the danger that lay there.
The plot thickens as Tam’s actions escalate. He hits Hong with a shovel, and Phuong, terrified, tries to flee but is pursued. The pursuit ends in tragedy when Phuong is struck on the road by Son, who had not realized the danger of the situation. Tam hides, while Phuong’s body is left in a state that necessitates a grim cover-up. Tam then switches Phuong and Hong’s clothes and locks Phuong in the basement, dragging the barely conscious Hong to the road where Phuong had been hit. He uses Phuong’s car to run over Hong, killing her and leaving behind a scene that confirms the heart Linh carries belongs to Hong.
The police intervene once more, but Tam fights to escape. Linh, meanwhile, is chased through the woods by Tam. Just as Tam closes in, the ghostly presence of Hong appears and protects Linh, leaving Tam stunned and terrified. The arrival of law enforcement halts Tam’s flight, though not before the frightening chase leaves everyone on edge.
In the aftermath, Phuong reconciles with her mother, and Linh and Son find happiness together, partially restored by the truth that has finally come to light. The closing scene returns to the water, where Cu Hu guides Phuong on a sightseeing boat, a quiet moment that also reveals the long-hidden truth: Phuong finally learns of Cu Hu’s unrequited love for her, a revelation that casts a bittersweet glow over the film’s ending.
