Death Bell

A group of twenty high school students enters an elite class designed to prep them for a college entrance exam. I-na is rebellious, with her best friend Myong-heo and the class clown Hyun who secretly loves I-na. The pressure and dynamics in the classroom establish the tense, high-stakes atmosphere that frames everything that follows.

Beom reports seeing a ghost haunting his paper, an ominous omen for the class. At the same time, Hwang Chang-wook discovers scars on his hand, hinting at a growing danger. The two events foreshadow a crisis that will engulf the students.

The class is confronted with a deadly game when a TV shows Min Hye-yeong trapped in a glass chamber filling with water. A PA voice declares that questions will decide who dies and warns them not to leave the school. The tone shifts from exam fear to life-or-death peril.

The class fails to solve the first question quickly enough to save Hye-yeong from the water-filled chamber. The death game begins to claim victims, forcing the students to confront the deadly trap within the school. The stakes rise dramatically as fear takes over.

Despite the warning, the class tries to leave, only to discover a teacher and hall monitor, Mr. Lee, beaten to death. Security guard Mr. Kim remains the lone safeguard as chaos spreads. The escape plan collapses into a brutal, unpredictable nightmare.

The students split up to answer the questions while searching for a way out. The brutal games are orchestrated by a mysterious woman, and each puzzle carries clues relating to Kim Ji-won, a student who died earlier that year. The conspiracy behind the tests begins to unfold.

I-na discovers that the victims’ deaths align with their ranking on the last test, revealing a cruel and calculating mechanism. The revelation deepens the mystery and increases the urgency to survive. The class begins to understand the personal stakes behind the questions.

Beom, previously placed in a mental facility after trying to strangle I-na, escapes and resumes his assault on I-na. Hyun sacrifices himself to shield her, dying in the process. Chang-wook then kills Beom to stop the immediate threat.

I-na learns that Myong-heo has been kidnapped by the mysterious woman guiding the games. The danger becomes personal as Myong-heo's fate hangs in the balance. The remaining students realize someone inside the school is orchestrating everything.

The trap is solved, but Myong-heo is dropped from the roof and dies. Chang-wook ascends to the roof and strangles the killer—later revealed to be Ji-won’s mother. The connection between past injustices and present killings becomes chillingly clear.

A memorial is held for the students killed in the games, a somber pause amid the chaos. Soon after, I-na is kidnapped without anyone noticing, deepening the sense that the mastermind is always several steps ahead. The school reels from the double blow.

During the final question, the truth erupts: a now-demented Chang-wook confesses to killing Ji-won. He is killed by the mastermind, Mr. Kim, the security guard, who has engineered the game. So-yeong frees I-na as the web of deceit begins to unravel.

Flashbacks illuminate Ji-won's confrontation with Chang-wook over the bribed entrance, her death, and the parents’ ruin. Beom descends into madness, convinced Ji-won has haunted him since her death. Mr. Kim and his wife plot further revenge against those they deem responsible.

The film ends with I-na revealed as the top of the class ranking, suggesting Ji-won's influence persists. Beom’s attacks are tied to the sense that Ji-won still occupies him, leaving a somber note about memory and vengeance.