Collect the 2 Shells to your left and go through the doorway in front of you. Kill the Grunt and collect the Double-Barrelled Shotgun. Turn left at the end of the corridor and kill the 2 Grunts. Continue down the diagonal corridor, ignoring the 2 Zombies in the lower half, and turn right at the end. Ignore the Zombie and collect the Green Armor, then turn around and go through the doorway towards the right (the one you didn't come from). Follow the corridor, collecting three 25 Health, and kill the 2 Grunts at the end before returning to the place you found the Green Armor. Continue down the corridor to kill a Spawn and Rottweiler. Continue through the next doorway and kill the Rottweiler in the corridor. Ignore the doorway to the right and instead go through the doorway straight ahead to kill 2 Knights, then return to the previous room. Go through the previously ignored doorway, this is one long twisty corridor that leads to a doorway behind the room with the 2 Zombies. Kill the Rottweiler to the left and Rottweiler to the right, then follow the corridor to the right. Turn left at the end and follow the next section of corridor, killing the 2 Rottweilers, and turn right at the end. Enter the next room and kill the Ogre and Scrag, then go through the doorway on the opposite side of the room. Kill the 2 Grunts. Turning right would lead back to the room with the 2 Zombies. As there are no explosives in this map or a Quad Damage, it is nearly impossible to kill the Zombies. It is possible to use the Spawn to kill the Zombies, though all four must be extremely close together (in-fighting is recommended and even then it takes good timing).