DOOM 2

Map 5 - The Waste Tunnels

Proceed through the level until you find a dark corridor. Shoot down the enemies in that room and go to the right. You should be locked in a room with black squares either side. Open them, kill the enemies and press all of the switches once. The entrance should open back up (the way you came in). Back in the dark hallway, take the far left turning. At the end of this room there should be a blue orb. Take it, exit and walk towards the wall that elevates via the dark hallway. Now you should be in a room with enemies behind bars. Shoot all 4 enemies to your left as you walked in with a shotgun (2 barrelled) with one bullet. If there isn't 4 enemies huddled together, go down the stairs. There's a room of 4 there.