Ventriloquist Tengan's wife Kazuko is bludgeoned to death with a trophy. Afflicted by multiple personality disorder, Tengan confesses that he may have killed her while he was unaware, but based on the circumstances, Tengan's apprentice Togawa, who was having an affair with Kazuko, rises as a suspect. Conan feels as though something is wrong with the case and investigates Tengan's home with Detective Takagi. He examines the sideboard where the trophies are displayed and realizes what has been bothering him. Later, Conan asks Takagi some questions and closes in on the truth behind the case..