The mansion owner, Kakuzô 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 Kakuzô's wife, Eiko, and then shown to the living room. The group rushes to Kakuzô's room after a power outage and a loud crash. Kakuzô screams to not come in the room, but the butler and maid disobey to find Kakuzô hanged and his 50 million yen vase broken. The police determine Kakuzô was murdered and attempt to analyze a blood covered book that could be Kakuzô's dying message.