After gathering all the goodies you could in the last episode you are reduced to no armour, an axe and the shotgun. Quickly get the amour and nail gun. Shoot the left red switche to open the door across the gorge. Kill the fiend that leaps across, then shot the ogre across the gap. Look down to the left and locate an entrance below. There is another fiend below, shot it from the saftey of the ledge, then drop down and run into it avoiding a zombie. Use the lift to find a secret containing the 100 health bonus.
Wade through the water, then go through a doorway.Get onto the lift, and ride to where you killed the ogre earlier. Go through a hall with a nail trap and get the double-barreled shotgun. Kill the knights and the ogre on the ledge.
Go to the right and work your way through the spiral staircases, taking care of several ogres and knights. Follow the ledge to some steps. Get the nail gun and the quad damage. Run on killing everything that moves. Jump the ledge and press the button on the wall, you'll be pushed into a room with a shambler, nail it while you still have quad. Grab the gold key, and shot the red button on the wall behind you, and keep killing while you still have quad damage. Look out of the window to the left, kill the ogre in the next building, the knights and another ogre hanging out on the ledge. Jump into the water and turn right, go up the stairs, and find another secret area and a grenade launcher. Swing back to the window and drop out carefully on to a ledge. Get the yellow armour. Carefully hop from the window and land on the ledge. Grab the yellow armour and walk to another secret area containing the 100 health bonus. Go through the portal and open the gold key door. If you haven't killed him already from a window, kill the fiend you find on the platform. Go over to the other entrance and kill the knight and ogre. Make your way to a stone path, kill the zombies and ogre. You can exit the level now, if you want 100% kills you'll need to kill the zombies in the moat where you started, and a fiend in the water below.