Psychiatrist Dr. Man Terrance Lau is tormented by nightmares in which a woman screams behind a half-closed door, a haunting that gnaws at his judgment and bleeds into his daily life. These visions push him to probe the private lives of patients, a habit that clashes with ethics and draws the ire of the Hospital Authority, whose hearings he attends to privately investigate backgrounds. Even the hospital director, who usually backs him, growls that this is the last time he will offer support, signaling a tipping point for Man.
One night, after a grueling shift, a taxi ride home becomes the hinge of the story. The driver, Choi [Nick Cheung Ka-Fai] is visibly exhausted and unfocused, admitting that he hasn’t slept well for years and has been haunted by nightmares. Man hands Choi a therapy card, but the other man discards it, seemingly resistant to help. Soon after, Choi drives the wrong way through a tunnel and crashes, getting arrested as a result. The crash serves as a catalyst, pushing Man to conduct a psychiatric evaluation and draw Choi into a dialogue about his dreams. As Choi reveals being pursued by countless ghosts and a persistent fly, he breaks down, terrified that his wife will die without him, and is returned to custody.
After the intake, Man encounters Dr. Ching, a former psychiatrist who claims the ability to enter people’s dreams. Skeptical at first, Man listens as Ching hints that confronting his nightmares directly might unlock a form of freedom he’s been seeking. This encounter nudges Man toward a more invasive approach, even as he contemplates sedatives and electroconvulsive therapy to coax sleep from Choi. Choi’s nightly terrors persist, intensifying until he bites a tooth in fear, a stark image of the torment that grips him. Donna [Rebecca Zhu], Man’s assistant, understands that Man’s curiosity will likely override caution, and helps him pull a background check on Choi and Fiona, Choi’s wife.
Man goes to Fiona [Fala Chen] to press further, and the scene at her home is unsettling: the house is in disarray, crammed with feng shui trinkets, and Fiona appears unstable. Mistaking Man for an old acquaintance, she invites him inside but soon has an emotional collapse, begging him to leave her and Choi be. He flees, shaken. Through a contact, Man uncovers that Choi was once a talented financial analyst who lost a close friend’s money during the 2008 financial crisis and quit his job. Choi’s ex-boss supplies surveillance footage showing Choi altering a document on his last day of work before collapsing in tears.
In their next session, Man lays out his findings to Choi and pieces together the truth: Choi isn’t guilty of losing the money to his friend; he’s guilty of betraying him. Recollections of the past reveal Fiona’s debt to the crisis era, and Choi’s involvement in a contract modification that drained their friend’s savings to repay the debts, precipitating bankruptcy and a tragic suicide for the friend and his family. Visiting the burned-out house of the friend, Choi confronts corpses surrounded by flies and a photograph bearing a note of revenge, which deepens his nightmares. He breaks down again, apologizing, and Man counsels that genuine freedom from the nightmares only comes with admitting guilt.
After this, Man confronts his estranged father [Ben Yuen] about the roots of his own torment. He reveals that the nightmares stem from his father’s brutal beatings of his mother, who later killed herself after the family’s money was stolen—an act that Man himself ultimately committed to cover up. His father’s apology opens a path to reconciliation, softening the fractured relationship between them.
Meanwhile, Choi, now imprisoned for fraud, is visited by Fiona. She cannot bear their separation and, overwhelmed by grief, takes her own life, leaving Choi utterly devastated and alone with the consequences of their shared past.
In the mid-credits scene, Dr. Ching locks himself in a hotel room and enters Man’s nightmare, revealing that Man has altered his own dream—manipulating the scenario so that it appears he actually pushed his mother from the building. The twist casts a shadow over the film’s events, suggesting that the line between nightmare and memory is not as clear as it seems and leaving Man to confront the possibility that his own forgiveness may require an admission he’s still avoiding.
