So-yeon works as a groomer in a pet shop, but has claustrophobia due to childhood trauma. A woman comes to the pet shop to collect her Persian cat, Bidanyi. The next day, the woman is found dead in an elevator, but Bidanyi is unharmed. The police investigate, but are unable to determine the cause of her death. So-yeon sees the crime scene and recognizes the cat. Her friend Kim Jun-seok, one of the police officers investigating the murder, gives her Bidanyi to look after.