The East Wing

Position
To the left is the East Wing entrance, attached to the courtyard by a small drawbridge. The large, locked double doors lead to the East Wing. Also nearby are three small wooden doors. The north-most door nearest to the small bridge leads to a small room with a couple random items, the next door leads to a basement area with a Ghoul, a Lesser Vampire, and some random items, and the final door (to the right of the East Wing entrance) leads to a basement area where your dog Buster is locked in a cage guarded by 3 Gypsy henchmen.

General
To enter the East Wing, you'll need to find the East Wing key. This key is randomly located somewhere in the Main Courtyard. It usually appears in one of the 6 side rooms near the East Wing and West Wing entrances. Be sure to search carefully for the key, it can sometimes appear in an out-of-the-way corner of one of the side- rooms, hidden in the shadows.

The East Wing is the first area of the game you'll be exploring. It is also the least symmetrical and least linear of the Castle's 3 main areas, which makes it probably the most difficult to navigate. Fortunately, Father Aville has helpfully marked the path you need to take with a green glow. When you come across a door with a glowing green light around it, you'll know that door is the correct path to your next destination. The green lights will lead you to the keys and the bosses, but won't point out the location of your randomly placed relatives. So you will have to search the various side rooms to find them, as well as to stock up on items and ammo.

The Garrison I
The Garrison I consists largely of a path of stairs that lead up several floors, each floor containing a room with random enemies and item chests. Inside a room on the top floor is the East Tower key. Have your Crucifix out, because a few Shadow Vampires will spawn inside the room as soon as you pick up the key.

The East Tower
The East Tower door on the 2nd floor leads to an elevator that will take you all the way to the top of the East Tower. Here's you'll find your Aunt Sophie dangling from a chain attached to the ceiling. Follow the staircase up, killing the 3 gypsy musketeers that snipe at you along the path. When you're almost at the top, a section of the staircase will crumble. You can either jump across, or carefully walk across the single remaining wooden beam that spans the gap. At the top of the East Tower are 3 large health kits and a final staircase that leads to the roof of the Tower and a boss fight with Desmodaui. As soon as Desmodaui appears, the staircase will lock behind you, trapping you on the Tower. After beating Desmodaui, you should notice a greenish glow coming from behind a pile of wooden beams. Jump over the beams to find a staircase leading you to an adjacent rooftop. Jump down the hole in this roof to reach a large storage chamber filled with crates and items. A large black metal coffin in this chamber is where Desmodaui regenerates from combat. Stake him before he can rise to kill him and take his Desmodaui key. This key unlocks the staircase back down to the East Tower, the chain mechanism on the roof holding Aunt Sophie, and a trapdoor in Desmodaui's coffin chamber that leads to the next area of the East Wing. This new area eventually leads you to the Garrison key.

The Officer's Quarters
The Officer's Quarters are a pair of long hallways, each containing several doors that lead to small bedrooms. Your goal here is to find the Major's Quarters, inside of which is the Garrison key you've been searching for. As always, go through the doors with the green glow around them to get there. The side rooms don't contain anything except random items and enemies, so only search them if you're still looking for missing relatives.

The Garrison II
When you finally retrieve the Garrison key, you can access the Garrison II through any Garrison II door. Going down to the bottom of the Garrison II brings you back to the 1st Floor of the East Wing, close to the exit back to the Main Courtyard (go here if you're dragging any relatives that need dropping off). If you're ready to fight Succubus Moraie and rescue Greg, climb upwards through the Garrison's several floors. At the top you'll find an elevator that will take you up to the Garrison roof. From the ladder that takes you onto the roof, turn left and follow the roof to see a cutscene showing your brother tied up on top of a nearby tower. Continue forward until you see a large hole in the roof. Slide down to the edge of the roof until you're close enough to the ground to drop through the hole without taking damage. Here you'll find a few chests as well as a wooden staircase that takes you up to the tower. Once you reach the tower, Succubus Moraie will appear. Kill her and use the key she drops to free Greg. Search the chest next to Greg for Father Aville's Heavenly Scroll that unlocks the path to the Crypt and Moraie's tomb. Backtrack all the way back down Garrison II until you hit the bottom to reach the crypt.

The Crypt
Since Moraie's coffin is located in the Crypt, you'll need to go there to finish her off permenantly. The entrance to the Crypt is located behind the huge boulder with a glowing glyph on it, located at the bottom of the Garrison II staircase. To move the boulder, you'll need the Heavenly Scroll, which is inside a chest guarded by the Succubus Moraie. Behind the boulder is a trap door. Drop down it for several feet and you'll land right on top of Moraie's coffin (you'll take some fall damage, but there's a couple health kits lying around Moraie's chamber to help you out). Stake her and claim the West Wing key she carries. Unfortunately, you can't climb back up through the trapdoor, since it's a few dozen feet above you, so you'll have to make your way through the rest of the Crypts looking for an exit.

As you move through the Crypts, zombies will emerge from the floor behind you and attack (zombies are the only enemy you'll face in the Crypt, but there's a lot of them). Instead of rushing forward and causing several zombies to appearing, try to move forward slowly, stopping every several feet to see if a zombie is starting to pull its way out of the ground. Eventually, you'll reach an elevator that takes you up into the Castle's Graveyard. The Graveyard is also, of course, crawling with zombies. Make your way to the Southeast corner of the Graveyard's outer wall, and you should see a pair of stone double doors on the outer wall. These doors will (finally) take you back to the Main Courtyard. Hopefully, you've managed to rescue all 5 East Wing hostages and can now proceed to the West Wing.