Castle Dimitrescu is the home of Alcina Dimitrescu and her 3 "daughters", Bela, Daniela and Cassandra. It is also one of the larger sections of the game, as it has many floors and multiple buildings.
After venturing through the basement and making your way across the courtyard, you will arrive at a room called the Hall of Absolution.
The room contains four statues that can be rotated, with a pool of blood in the center. Across from the entrance is a plaque that reads:
"Women are blind to male advances, but the poor shall take their chances to give their lord their bounty sown, so that soon the wine may flow."
This riddle provides the solution to the puzzle: the women must face each other (as they are blind to the male advances), while the poor must face their lord (the man on horseback). The lord should face the hooded woman, again symbolizing that women are blind to male advances.
Once the statues are positioned correctly, the pool of blood in the center will drain, revealing a passage below.
After making your way past the Library, you can proceed to the Atelier, where you'll find a message that reads:
"Let the five bells of this chamber ring out."
This hints that you must shoot the five bells visible from within the room. Each bell will ignite with a small flame once hit.
The first bell is a small one sitting on top of a glass-front display cabinet next to a framed picture.
The second bell is slightly larger and rests on a small table.
The third bell is attached to one of the pendulums among the spinning cogs.
The fourth bell is inside the chandelier. Using the stairs to get a better angle makes it easier to hit.
The fifth and final bell is outside the window, visible from the top of the stairs in the tower.
Once all five bells are lit, the large painting beneath the window will slide open, revealing a hidden passage.
After progressing through the castle and solving its various puzzles, your final task is to unlock the Hall of the Four and make your escape.
To do this, you must collect the four masks scattered throughout the castle:
Each mask fits into a specific bust in the Hall of the Four. The number of holes in each bust indicates which mask belongs there — one hole for the Mask of Joy, two for the Mask of Sorrow, and so on.
Once all four masks are placed correctly, the main exit will unlock, allowing you to leave the castle.