The film spans over seven adventurous days inside an apartment building. Yoon-joo is a college lecturer with plenty of time on his hands. He gets annoyed at the sound of a dog barking and tries to find out where it’s coming from. Coincidentally, he discovers a dog in front of his neighbor’s door, and thinking it’s the culprit, he kidnaps the dog and locks it in the basement. 

Hyun-nam, a secretary in the apartment’s superintendent’s office, is bored to tears with her uneventful life. She kills time with a crossword puzzle until a little girl comes in with a notice for a lost dog. Hyun-nam, suddenly animated, starts putting up notices all over the neighborhood at her own free will. However, as days go by, more dogs start to disappear. Then one day, Hyun-nam goes up on the apartment roof and witnesses a man killing a dog on the rooftop across from her.