can't get it, jump in the pit of Demons, get to the teleporter, and try again.

If playing on skill levels 1 or 2, turn around and head back down the stairs. Get to the lift and then to the opening in front of it (not blocked by bars). Press Circle to lower it, get on, and ride to the top.

If on skill levels 3 or 4, jump in the river of Demons. Kill them and go through the opening at the end of the river. Grab the Medikit and step on the teleporter. You'll be teleported in front of the "Crusher" with Hell Knights. Hit the switch next to the lift to activate the Crusher. Get back to the lift, lower it, get on, and ride to the top.

Up here, turn left. Kill the Shotgun Guys, Heavy Weapon Dudes, and Spectres in the new opening. Collect health and ammo, then open the Blue Door to the right.

In here, head straight and hit the switch to your left. A lift behind you will lower. Get on and ride to the top. Head down the stairs to your left.

Follow this hallway to a door, killing Imps or Shotgun Guys. Open the door and go through. Hit the switch to your right; the lift will lower to your left. Drop down to the floor below. Open the door in front of you and go through.

Head up the staircase. As you ascend, two walls will open, revealing Heavy Weapon Dudes and Revenants. Kill them and reach the top. Grab the Shotgun Shells and the Red Key across from you.

The platform will lower, revealing Spectres. Kill them, and the platform will lower to ground level. Get the Energy Cell Pack, open the door, and leave. Hit the switch to lower the lift next to you, get on, and ride to the top.

Up here, open the door and go through. Back in the hall, follow it until you see an opening to your left. Skip the first opening and go through the second one.

Open the Red Door in front of you and go through. Head right and cross the walkway into an opening. Go through the opening to your right.

Kill the Heavy Weapon Dudes and Shotgun Guys, then head through the opening across from you. Open the door to your left and go through.

Head left and follow the pathway to a pillar with the Yellow Key. Hit the switch next to it to lower the pillar and grab the Yellow Key. Heavy Weapon Dudes, Shotgun Guys, Imps, and Spectres will be released. Kill any that teleport near you.

Step through the teleporter next to where the Yellow Key was. You'll be teleported to the room in the middle of this area. Kill the remaining enemies and hit the switch.

Turn around and go through the opening across from you. Cross the new pathway to the Yellow Door, open it, and go through. Kill the Nightmare Spectre and hit the exit switch.