Digimon Frontier

KaiserGreymon and MagnaGarurumon, along with the rest, arrive at Ophanimon's Castle. When they enter the Castle, they encounter the Castle librarian and caretaker Nefertimon on the balcony. She has no clue on where the Digi-Code key is so the gang splits up. Meanwhile, Crusadermon asks Lucemon if the Royal Knights still had an agreement to take them to the Human World but Lucemon sends them on their way. Later that night, the search continues and Takuya accidentally makes some books fall during the search and then he falls asleep. The group reunites but no one had located the key. The next morning, the Royal Knights appear and start to attack.