The mansion owner, Kakuzo Okudaira, explains to Kogoro the person who murdered his son a year ago might be someone living in his household and the murderer might return to kill him next. Conan, Kogoro, and the rest of the group is introduced to Kakuz... (more)o's wife, Eiko, and then shown to the living room. The group rushes to Kakuzo's room after a power outage and a loud crash. Kakuzo screams to not come in the room, but the butler and maid disobey to find Kakuzo hanged and his 50 million yen vase broken. The police determine Kakuzo was murdered and attempt to analyze a blood covered book that could be Kakuzo's dying message.