Although Aridden is a dangerous city for Kaito to stay in, he will still need to remain in the city for a few more days, at least until he can sell some Moon Crystals to buy better items and fight the boss of Floor 2. He will never again make the mistake of working with other Duelists or adventurers, at least not on purpose.
So, before returning to Earth, he stops by Crimson Castle, opening the trans-dimensional door there.
Through the trans-dimensional door, Kaito emerges inside the Crimson Castle.
As always, the atmosphere is gloomy, with dark stone walls. He hears the echo of his footsteps as he leaves his quarters. As Yulia must still be sorting out the Hólis situation, her aim is to find Alex, her apprentice, to assess his progress as a vampire.