Kill the ogre the other side of the wall. Hit the red stone and continue forward. Jump in the water if you need yellow armour and cells. Take a lift back up to the bridge, kill the death knight and turn right at the intersection. Once in the hall, turn right. Then turn left to blast another death knight guarding a switch, this switch lowers a temporary staircase to another button. Go down the other side of the hallway, grenade the vore hiding around the corner. Now explode the ogre on the ledge. Return to the first button, press it, and run back to the staircase to the second, press that button and kill the new ogre that appears in the doorway below from the relative safety of this ledge. Now enter the room beyond and snipe the two ogres on the ledge above. Drop into the water and explode the zombies. Swim up to the entrance take out more zombies. Go left kill yet another zombies. Enter the room and look up to the doorway, kill anything that peaks over at you. Jump up on to the bars and continue making your way up and around. Go through the doorway above and kill any remaining death knights. Press the button on the wall, and snipe the ogres across through the bars. Drop back down and take the the right hand fork. Kill more zombies. Make your way to the top of the building, then drop down onto the little balcony. Hit the post and get the message that the center bridge has changed. Jump through the new opening and enter the water, kill the zombies and collect the quad damage from the secret area in the corner. Get out of the water, ride the lift up again, and head through the arched passageway ahead. Kill the death knight, ogre and zombies, then jump out the window and head back to the bridge at the begining. Cross the bridge and enter another hallway with some yellow armour and a death knight to the right. Now deal with the ogre on the lift to the left. Get onto the lift, and be prepared for the ogre and death knight at the bottom on the right. Enter the next room, kill another death knight, and hit the button on the wall. Get back on the lift and be perpared for another ogre and death knight. After you have dispatched them shoot the ogres behind the bars. Shoot the wall to the right and drop into the other secret area. Gran the 100 health bonus and pentagram of protection. Ride the lift back up, armed with explosives run up the steps and kill more death knights. Hit the button to free the ogres and some zombies. Follow the passage around to the left to room containing a vore. Kill it and hit the button. Return to the central lift. Kill the ogre at the top, grab the thunderbolt and continue up the stairs, deal with the death knights. There is a vore guarding the gold key in a room off to the right, kill it and grab the key.
Make your way back to the gold key wall. Shoot the ogre and hit the post to change the bridge again. Return to the bridge, Cros over and kill the zombie, a vore will appear, kill it and the floor begins to sink. An ogre appears, and then nail traps, then zombies. Finally, the floor stops sinking and a one of the walls moves, revealing another two vores.
Once it's open, strafe in and out of the doorway, and take care of the two vores inside. Now, run up, grab the rune key from the pedestal, and exit this godforsaken place!