In the center of the bustling city, a series of bizarre disappearances occurred in an apartment building that was in disrepair. Three unrelated people disappeared without a trace in the middle of the night. The only intersection was Room 502. The police were helpless and the deceased's friend pursued the case alone, but inadvertently came across the secret buried deep.
The secret passage behind the mirror, the ringtone echoing at midnight, the unknown basement... Every clue leads the truth to an even weirder abyss. And when the police detectives came face-to-face with the criminals, they discovered that there seemed to be a bigger mystery hidden behind it all.
As the truth gradually emerged, the bells in the apartment building never stopped ringing. Is Room 502 the door to the truth or an abyss swallowing life?
