After picking up the book, continue to the left. Climb up and collect the dust ahead.
Continue to the left. There's an iron door on the right that won't open. You'll need to crouch to pass through the area ahead.
Crouch your way forward. There are many enemies in the courtyard ahead. As before, prioritize taking out the bell-ringers first, then deal with the archers on the towers.
After defeating all enemies, you'll obtain Black Stone Fragment #2.
