One morning, Takahashi, a writer who has just stayed up all night working, is interrupted by a phone call from his old friend Sonomura: barely able to contain his excitement, Sonomura claims that he has cracked a secret cryptographic code based on Edgar Allan Poe's The Gold-Bug and now knows exactly when and where a murder will take place--and they must hurry if they want to witness the murder, because it's later that very night! Sonomura has a history...