Synopsis

He secured the marriage registration form within an envelope, then locked his computer with an eight-digit password. The envelope's whereabouts would be revealed only upon entering the correct code. Suspecting the puzzle might require more than one page, Conan and his companions began searching the room for a missing sheet. While searching, Yumi observed that the code sheet was a duplicate, not the original. This detail provided Conan with the key to solving the mystery.