Follow this Doom 3 walkthrough to survive the Mars City Underground level. Learn enemy tactics, find weapons, and progress through the UAC facility.
Alright, so you've just dropped into what feels like the belly of Mars. Don't worry, it's not so bad once you get the hang of it. First things first, grab the goodies lying around – you'll find a pistol and an SMG. Then, take a leap down the shaft. Don't freak out, you'll get a flashlight down there, which is pretty essential for what's coming up. Keep crawling through the shaft; you'll find some grenades tucked away.
As you're about to exit this cramped shaft, keep an ear out. There's a Commando-Zombie waiting on the floor above you. Take him out, and you'll snag a Chaingun. There's also some ammo for it near the bay door, so grab that. Now, here's a little trick: don't go through the bay door just yet. Instead, backtrack a bit to where you first entered this level. There's another Commando-Zombie chilling in the previous room. Deal with him, grab the Chainsaw and any other supplies you see, and *then* head back to the bay door and open it.
Okay, this next part looks a bit grim, but we've got this. As soon as you step out of the bay door, get ready for a swarm of Trites. They're annoying, but easy to take down. Once they're cleared, head into the hallway. When you get to the door at the end, two Commando-Zombies will pop out. Take them both down, grab the loot – including a sweet Plasma Gun – and then climb the ladder in the small room nearby.
At the very top, there's some armor waiting for you. Grab it, then hop into the shaft. When you reach the end, you'll hear and see a Commando-Zombie. Don't let it get the drop on you! This is a perfect moment to try out the Soul Cube if you have it. Drop down and quickly use the Soul Cube on the Commando-Zombie. It'll drain its health and yours, and the zombie will be toast. Pretty neat, huh? As you head down the stairs, another Commando-Zombie will attack, so take care of that one too. When you get close to the garage door, watch out – an Arch-Ville is about to show up. You know the drill: take it down! After it's dead, head back up the stairs. As you approach the door, another Arch-Ville will appear. Blast that one too, then enter the door, call for the lift, and head down.
You'll soon encounter another Commando-Zombie near a door. Take it out (the Soul Cube really makes these guys easy!). When you enter the next room, a Revenant will attack. Deal with it, then move into the room beyond. Use the elevator here to go up to level 2.
This time, unlike some previous encounters, there's no one waiting to ambush you. You'll find only one door you can enter. Go through it, and you'll meet Swann. He's got some news: Sarge was apparently working against you the whole time, and Campbell went after Swann. Grab Swann's PDA – it's got some important info and your next objective.
NEW OBJECTIVE: Using Swann's PDA, gain entrance into the CPU Complex.
PDA UPDATE:
- User Data: Elliot Swann, UAC Corporate, Counsellor, Security Clearance: CPU Complex.
- Audio Log: Heading to Communications Facility - Swann is going to stop all communications to prevent doom.
- Audio Log: Heading to the Caverns - Another portal created by demons needs destroying as the fleet arrives.
- User Mail: From UAC Board to Swann - Reviewing Mars operations, need to control Betruger's research as it risks teleportation experiments.
- User Mail: From Liz McNeil to Swann - Pleased about the review, worried about Betruger, reassigned to Earth, hopes intervention isn't too late.
- User Mail: From Malcolm Betruger to Swann - Thinks the review is unnecessary, needs more money and time for his research that will change mankind.
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