Mission 12: Vega Central Processing

Enter the control room and grab the Data Log before moving on. Outside, check behind the crates and debris on the right to find an Elite Guard. As you continue there are two paths; going through the greenly lit maintenance room to the right is the most rewarding.

At the end of the shaft behind the maintenance door you'll find the Quakeguy collectible. There's also a BFG cell at the dead end of the shaft.

Mission 12 - Quakeguy Collectible

Go down the yellow walkways and kill the Imps. Try taking three out with a Frag Grenade for a challenge. Head through the maintenance door and open the hatch at the end, then drop down.

In this area you must turn off two security switches. Once you pull the first one, demons emerge. There are two powerful powerups in the middle of the area; a Berserk and an Invulnerability. You're up against another set of demons after the first fight, so you should only grab one for each fight. The first fight is against various Possessed Soldiers, Imps, a few Revenants and Mancubi. In the second fight, which starts after using the main control system, you're up against several Cacodemons, a Hell Knight, Cyber-Mancubus and some Hell Razors and a Possessed Security.

After clearing the area, head through the large door. Ignore the hallway to the right for now - you'll reach it later. Instead go through the door and turn left. Defeat the monsters in this area, then check the falled over cart in the corner for a Data Log. The elevators up ahead contain two Possessed Soldiers (the one to the right) and a BFG cell (the one to the left). To continue, open up the hatch behind the crates in the area where you found the Data Log and drop down.

Defeat the Possessed and Spectres in this area; remember that Spectres aren't armored and so especially vulnerable against teh Super Shotgun. At the end of the walkway, snatch the Blue Keycard from the dead body and go through the door. (You'll now be in the walkway we previously skipped over, the one that was initially to your right as you passed by.) Head through the door to your left, use the AutoMap station and head through the next blue door, then kill the Revenant.

There are three secrets in close proximity here. The first one is obvious: The Elite Guard.

Mission 12 - Elite Guard #1

The second is less obvious: The Classic Map Lever behind the crates the Elite Guard is leaning against. Go back to the area where you found the Blue Keycard to spot the Classic Map.

Mission 12 - Classic Map

The third one is found after dropping down the hole to the left of the Elite Guard (in which you'll automatically fall through a Mega Health). In the icy area, turn right to the dead end and drop down. The Jungleguy Collectible is at the end of this lower walkway.

Mission 12 - Jungleguy Collectible

Continue through the vent shaft at the end of the walkway back up and drop down to proceed. The elevator here takes you back to the previous area; otherwise head in the other direction.

In this area you'll need to destroy four cooling coils. After destroying the first, all hell breaks loose. You're up against Imps, Possessed Soldiers, a Summoner, Hell Razors, a few Revenants and Mancubi and a Baron of Hell. A last Baron of Hell shows up after destroying the fourth cooling coil. Use the BFG on them since there's ammo lying around for it. There's also a Berserk Powerup in a niche in the far corner (check the map or before initiating the battle) that helps tremendously.

After clearing the area and collecting all pickups, head up to the elevator in the (initial) far right corner. Use the panel to make it move up and drop down at the end on a train. At the end you'll face a true shitload of demons. Pull out your BFG beforehand and as soon as the doors open, shoot at the two Barons of Hell fighting other creatures in the distance. Clear anything else with the Gauss Cannon, then pull out the Super Shotgun or Assault Rifle and go for lesser demons. More and more demons will show up. If things get nasty, use the BFG or Chainsaw on huge enemies.

Cleanse the place and make your way to the elevator in the back, but don't ride it up just yet. Use the Health Station on the left to heal, collect the Data Log to the right, then move *around* the elevator and drop down below. Climb up to find an Elite Guard.

Mission 12 - Elite Guard #2

Go up with the elevator, then use the large lift to reach VEGA's Core. Destroy it to end the mission.