You are gonna start this one off in the bay you exited the last level in. Explore the room a bit, look up and a guy will talk to you, telling you the power cells are knocked out, and you are given a new objective: find 2 power cells. Go up the stairs and to the door at your right, watch out for the Imp that will pop out of the left side of the hall. In this room there will be a zombie and two Z-Secs waiting for you. And continue to the next area, as soon as you walk through the door, a vulgar will come out of the ceiling. Before he can get into attack stance, blow him away. Continue forward and find an access panel, which you need to download a PDA to access. The door to your right is malfunctioning, so just go to the door straight ahead.

You will now come to a room, which there are broken stairs and a locker to your right, and then enter the code ‘937’, and go forward through the red, gooey tunnel. In this area you will be attacked by a group mixed with Imps, Vulgars and Z-Secs, keep going down the pathway and up the stairs, to your left will be another door which has denied access. So take a left. Straight through the walkway will be an Imp waiting in the darkness for you, after he is dead, take a right up some stairways. Download Ron Gibbon's PDA and turn around to kill the zombie. Head back to the door you just had access denied to and go straight into the office closest to the entrance of the room, take out the enemies inside, and collect health and ammo pickups in the area, go back to the hall and up the steps. Go into the room to your left and kill all the enemies inside, step back out and back into the hallway. You will see two pillars with a door in between them. Go to it.

In this room to your right you will see yet another door with denied access as you are ambushed by 2 Z-Secs. Go to the next door. Above you will see "Excavation Transfer" written above the doorway. This is a rather tall cavern with many ways to fall down. Kill the Vulgar that has popped out, and you will receive a new objective: "Locate a power cell to start the lift in Excavation Transfer". Now you've got a shiny new PDA to get access to that door back there. Retrace your steps to the door and into the newly accessed room. You will find a number of zombies waiting inside, and at the right of the room will be a locker. Look at your PDA for reference. Go back around to the left of the room and take out the power cell in the generator. You will be ambushed by two Vulgars, kill them, and continue back to the entrance of the room. Go back to the large cavern where you got the PDA from, kill the enemies in the area, and insert the power cell into the generator. Now go to your left where the lift is, and hop onto one of the box-like platforms, be careful, and hop off on the second level. On the platform, go through the door and continue down the hallway in it. In the room it leads to, kill all the enemies in it, and collect the PDA in the upper-left corner, turn around and go to the next room. Now In this room there is an arcade game called Hellanoid. Which can be very fun if you have A.D.D. like I do... Oh crap, I’m supposed to be writing the walkthrough. Anyway...

Head on into the next room, which will have 1 Z-Sec waiting for you in it. After that, head into the next room. This is the same room you were in before, but on the other side. Go to your left and down the stairs to the door that you should have access to, if you don’t, read above for reference. In this room, straight ahead of you is an access panel. Push the button! This will bring a bridge out for you to get across. Walk across the bridge, kill the Vulgar that spawns, and head on down the ladder to your right. Go ahead and take out the two power cells inside the generator near you, turnaround and leave the area. This will of course cause enemies to spawn. You will now find yourself in the room you were in a while ago. Take a right, killing enemies along the way, go through the room and straight through the second door inside the room. Kill the Imp and Vulgar inside. In the next room you will find yourself inside the room you started in. Put the two power cells into the generator, and go onto the lift near you, go up the lift, and a ladder will lower for you, you are now probably gonna link up with the guy who told you to get the power cells. But nope, he’s dead of course. Go down the ladder and down through the floor to get into the next area. The Door ahead of you will give you denied access, so head on into the elevator exit to Erebus Research.