Teleport 4 Main Chamber
Grab the guns and ammo on the right then drop down into hole and crouch, go through the tunnel to find more pick ups and then up into the next room and kill the chaingun commando.
Go through the left door and kill the commando then grab the armor and chainsaw. Go back and enter the bay door and kill the trites to your right.
The soul cube will tell you when it is ready to use. Head down the corridor where the trites came from and kill a commando and then another behind you.
Grab the plasma gun from an alcove on your right. Enter the lift shaft and climb the ladder, you’ll get armor at the top then turn right and crouch to enter the tunnel. Shoot the chaingun commando through the hole before dropping down.
Delta Service Tunnel 1
Head down the stairs and kill a commando – grab the shotgun on your right. As you walk along an archvile will appear ahead of you, watch out for him reviving the commando then grab the pick ups in the alcove he emerged from.
Head up the stairs and along the walkway and kill another archvile as you come to the door at the end on the right. Watch out for any enemies he has revived and go through the door and call the lift. Take the lift down, kill a chaingun commando at the bottom.
Delta Authority Systems
There’s a revenant up the stairs to your left. Climb the stairs and go through the door on the left. Call the lift and select level 2, Delta Authority.
Head round to the next door and grab Elliot Swann’s PDA on your left as he chats to you. Go through the door on the left.
Drop into the hole in the floor and crouch to crawl through the tunnel, climb the ladder at the end and turn to jump into the higher tunnel, follow it along to grab some armor and pick ups then use the control panel to extend the ladder and climb it.
Delta Main Lobby
Kill the archviles and the commandos and grab Bruce Jackson’s PDA from the darkened corner. Use the control panel to go through the next door and follow the corridor round.
Kill the revenant to your left and download the info from the information terminal. Grab the medkit on the left and the armor on the right then use the control panel to open the door and exit this level.