After seven years together, Yoon Ha-ri and Kang Dong-gu have grown complacent, mistaking familiarity for stability. One day, a torrential downpour leaves them stranded at a hotel, later revealed to be a place once occupied by a serial killer. As the rain traps them inside, unease builds in the confined space. Forced to face both a lurking threat and the cracks in their long relationship, the couple confronts what they may have lost.
