Go further east until you see the castle.

1. Head straight to the Throne Room, then choose "Yes" when prompted.
2. You'll have to fight a series of battles without a break, but enemies are weak so you shouldn't have any problem.
3. In the Crystal Room, you'll fight a scripted battle which you cannot win.
4. After the cutscene, collect items in the Throne Room.
5. Then go back to 2F, Inn, and rest to continue the story.

Chests/Items:

• I-013: Hermes Shoes - Throne Room, inside the pot on the left.
• I-014: Spider's Silk - Throne Room, hidden room, top chest.
• I-015: Demon Shield - Throne Room, hidden room, middle chest.
• I-016: Ether - Throne Room, hidden room, bottom chest.

You'll reappear in the king's chamber, East Tower 3F. From there, follow the map to collect the remaining treasures.

• After you leave the king's chamber, you'll be in the bar. You can talk to the dancer standing near the bar; choose "Yes" when prompted for a surprise.
• Inside the West Tower 2F, you can rename your party members by talking to the man in bed, Namingway. Optionally, you can talk to Yang's wife on 3F for some dialogue.

Chests/Items:

• C-061: Tent - East Tower 3F.
• I-017: Bacchus's Cider - East Tower 2F, inside a pot at the east wall.
• I-018: Zeus's Wrath - West Tower 1F, top-left pot.
• C-062: Bomb Fragment - West Tower 1F, top chest.
• C-063: Antarctic Wind - West Tower 1F, middle chest.
• C-064: Potion - West Tower 1F, bottom chest.