You'll find yourself in a bay you left in, exit the bay, and take aright, and find a door. In this room will be a rail to your left, ahead will be a dead marine, collect his soul, and fight the Z-Sec, Once he has perished, two Vulgars will spawn, Once you have cleared the area, head on up the stairs and through the door ahead of you. Continue forward, you will find another dead marine with a PDA next to him. Download it, and go through the double doors to your right. There will be a tram ahead of you, ignore it, and take a left to find a half-opened garage door. Head on under it.

In This room, there are many barrels scattered about the place, which could soon become your best friend, or your biggest annoyance. If you are prone to explosions, destroy the barrels before anything big happens. 3 Bruisers will now spawn, activate your artifact, and punch em' out. After that, head up the stairs and pathway that would be to your left if you were at the doors you entered in. Head into the next room.

This next area is just a big straight-away, with a number of Z-Secs scattered about the place. Kill them off, head forward and take on the Arch-Vile ahead of you. Once he is gone, 3 revenants will pop out at your right and front, kill them, head up the path to your right, and kill 2 more Vulgars that will spawn. Head through the large door ahead of you, where a Bruiser will be welcoming you on the other side. Kill him, head up the stairs ahead of you, killing many enemies (mix of Z-Secs, Wraiths, Vulgars, Arch-Vile) along the way. Eventually there will be a hall to your left, take it down the hall and go on through the door at the end of it. Now You'll find a rather large room with a teleport in the middle of the back wall behind plate glass, kill the Revenant to your left, then head down the ramp to your right, which is hosting a Revenant at the bottom, kill him and enter the large teleportation room. Activate your artifact, and kill the bruiser, and 2 Revenants in the room, then head forward to the control room ahead, have fun pushing buttons on this one! Select "Delta Complex", and head back into the room, where it appears a Bruiser has spawned to try and stop you, kill him, and head through the teleporter to Delta Labs.