"It's easy to get lost in this level, so read the guide carefully..."
1. There are four items at four corners of the elevator. Take them. Wait for the elevator to stops and head to the door with a Save Point near it.
2. After entering the door, you'll see a "door" with lots of wires strewn out across it. You can't go through it but we'll need it later. Look to your left, you can see a trio of Lying Figures walking aimlessly along the hallways. Get their attention by and try to group them. Quickly get the shotgun and blast them. Now get there quick and stomp them to dead.
3. Where to go next? Shall we get a secret weapon? If you want a secret weapon, follow the red arrow. Keep going straight ahead (do not turn right) and turn left, you'll see a "T junction". You can choose to enter "O1" or "O2" as both lead to the same place.
4. After climbing down the ladder, you'll reach a narrow hallway with Mandarins right below you. Unluckily, Pyramid Head can be found here. However, just run away from him until you reach a room in the middle of this "strange area". Inside the room, you'll see the Great Knife lying on the table (Pyramid Head's signature weapon) with some shotgun shells near it.
5. Now, leave the room, get to the ladder and climb up to the upper level of the labyrinth. From the "T-junction", keep going then take the only left, keep going straight ahead until you reach another ladder leading to the lower floor (see the above image). After getting down there, switch to the "Great Knife" and kill two "Lying Figures" or you can shoot them with the shotgun. Climb up another ladder and you'll see a huge cube in the middle of the room...
6. If the puzzle is done correctly, you'll be able to get to the stairs behind the "rotating room". Now, you'll have to descend the stairs and trigger a cutscene. After the cutscene, get back to the room with the "cube" and get the Wire Cutter behind the "cube" (You can only get it after watching the cutscene).
7. Now, get back to the "door" with wires strewn out across it. Use the "Wire Cutter" to cut the wires and continue. (Weird, why can't James cut it with the Great Knife?)