Kogoro Mouri received a letter and headed to Tsukikage Island. He then found out that the man requesting for the investigation was already dead. Asou Keiji was a world-reknowned pianist who killed his family and set his house on fire while playing Beethoven's Moonlight Sonata.
Conan couldn't stop the killer from committing suicide, but he played one last music piano code message while the building was burning away: "Thank you, little detective."
