Doom 3 Mars City is the third part in the complete Doom 3 walkthrough featuring Mars City and Mars City Underground levels.
Doom 3 Walkthrough
First, this guide assumes that you can spot the more obvious ammo pickups but does give locations of hidden or less-visible items. Also listed are objectives, enemies encountered, and tactics to get through the area. For the purposes of this walkthrough, the player's character is referred to as "player" or "the player" during cut-scene information.
Mars City
You'll find the following:
- 2 X PDAs
- 2 X Video Disks
Mars City Enemies
- N/A
Mars City Objectives
- Go to the reception.
- Perform all your duties in a military manner.
- Report to Marine Command.
- Search for the missing scientist. Locate Maintenance Entrance.
Mars City Overview
CUTSCENE: The player is informed about Mars City and the UAC, and once the ship lands, heads to reception, but not before overhearing two other passengers talking cryptically about Mars City.
Walk up the stairs and through the doors. Most of the people here don't have that much to say, so keep moving until you have to stop for the Bio Scan. Once it's complete, head through the door.
You'll be in a larger area - head up to the desk to complete the reception objective. You'll obtain your PDA, a priceless tool in Doom 3. Your PDA displays your current objective, weapons, items, and let you listen to audio logs, watch videos you collect from Video Disks, and read emails - when you see "PDA update", check it (BB) for new emails.
TIP: The PDA also functions as a key - depending on your current clearance, certain doors may be locked. Finding a higher-level access PDA and downloading its information to yours will let you gain access to previously locked areas. You'll receive emails from Director Banks and Sergeant Kelly, and a Video Disk of Marine Command Briefing. You can read them and watch the video if you want, but your objectives will be updated. Now, you need to head to Marine Command to report in.
Ignore the reception clerk and head to the previous room to find a data stand - these stands allow you to download extra information to your PDA, sometimes giving you valuable intel. Use the stand to obtain an email from the Safety Committee, which is just a clever way of telling you more about the basics.
Head back to the reception desk to find a Video Disk. Grab it and head further into the room. When you spot the next data stand, use it to get an email from UAC Security that foreshadows the coming events. The path is linear from here, so continue following it until you trigger a cutscene.
CUTSCENE: The two men from the player's ship reappear, looking troubled. Keep on moving until you find a door - don't enter it yet. Head right and you'll be in the cafeteria - there's a PDA to collect here and an interesting arcade game you can play. Grab the PDA to get an audio log by Adam E. Berneche, and his various emails. You'll find a code for a security cabinet (396).
Head back to the door you found earlier and head through to overhear a conversation (more foreshadowing) and find another data stand. Use it to receive more emails, then continue forward and head up the stairs to the right. A marine will give you directions - head left to see what happens, and then follow his directions until you find more stairs. Instead of going up them, head through the door across from them to find another Video Disk about Plasma Guns. Now, head up the aforementioned stairs to find yourself in Marine HQ.
CUTSCENE: The player is tasked with finding a missing scientist, and is appointed a sentry bot to show the way.
Follow the sentry bot (which you'll learn to love later on) until it performs its shutdown - that's your signal that you have reached your destination. You'll find a security cabinet here - enter the code from the email (396). You'll find some ammunition for the Pistol - enter the lift to head to Mars City Underground.
Doom 3 Video Walkthrough - Level 1 - Nightmare
Mars City Underground
You'll find:
- 3 X PDAs
- 3 X Oxygen Tanks
Mars City Underground Enemies
- Imp, Z-SEC Zombie, Zombie
Mars City Underground Objectives
- Reach old Com Building.
- Go back to Security Checkpoint.
- Return to Mars City.
Mars City Underground Overview
NOTE: Not all PDAs are collected by saving your fellow humans. Below is an example...
You'll find a room with a giant crane - shoot the crane operator (aim for the head) to have him drop his PDA, and collect it.
TIP: Use the controls for the crane to rotate it, and then head for the door at the end. Before you enter, turn left and you'll spot a Medkit - if you jump on that ledge and look to the left with the flashlight, you'll see a rope that goes across the chasm. It's possible to walk across the rope to the other side, though it's not necessary.
Follow the path (it's very linear; most FPS games are) and you'll find an individual who'll tell you a bit about the scientist - there are two Armor Shards under the stairs there. Continue until you find the two maintenance workers and look around to find a cabinet with goodies in it, and a PDA. The PDA will give you the code (531) for the cabinet, which has more armor and shells for the Shotgun.
Keep following the linear path until the lights go out - use your flashlight (WB) to navigate forward. You'll find a wounded Marine - kill him to get his PDA, and grab the bullets for the Pistol off the storage crate before exiting through the airlock.
You'll need to quickly head through the adjacent airlock to avoid dying from asphyxiation - your combat suit isn't equipped with hours and hours of oxygen. You can optionally head right before crossing the bridge to find oxygen and ammunition.
Use the elevator to go up a floor, and continue moving forward to find the missing scientist.
TIP: Before you head into the elevator, check behind the shelves on your right to find more armor and ammo (be sure to jump).
CUTSCENE: The scientist is highly agitated - a portal seems to be open, and he isn't happy about what's coming through.
Kill the scientist before he gets a chance to turn - consider it a mercy kill. Outside the door is a Z-SEC Zombie - aim for the head for a quick kill.
Take a look at the monitors to see what's going on - it's time to head back to the Security Checkpoint (the place where you were outfitted with the Pistol and armor), but first grab the Pistol ammo on the lower control panel.
Head back to the elevator to return to the service passage - from the top of the stairs, there's Pistol ammo to the right of you. Head downstairs, and kill the zombie in the alcove at the bottom of the stairs to your left.
Move into the next room and a zombie will crawl up to get you - shoot him. You'll be in the Energy Delivery room, so look for a short ladder to climb down to grab some Armor Shards.
TIP: There's a Shotgun down here, so grab it, but beware - once you do, you'll be dropped into a small room surrounded by zombies.
Climb back up to the upper level, and find the control panel - it makes a bridge for you to use. There's a Z-SEC Zombie at the other end of the bridge, so be ready for him.
When you enter the Energy Processing room, a Z-SEC Zombie will start shooting - gun him down and keep an eye out for the Zombie that crawls after you here. Check the lower level to find a PDA. Climb the pipe here to find some armor and health (if you need it).
That last PDA gave you clearance to get through the locked door - ready your flashlight, the corridor is pretty dark. There's a Zombie at the far end around the corner, so be ready for him. A Z-SEC Zombie will appear, so shoot him and check to the right to find a small cache of Shotgun shells.
In the next room, take out the Zombie and grab the Shotgun shells and armor on your left. Keep your Shotgun handy for the room coming up - there's a gas leak that's spewing fire across the path, so go to your right to fight your first Imp. Blast it with the Shotgun for an easy kill, and then proceed to the next room.
Here you'll see a keypad for the busted valve - enter 842 to stop the gas leak, which opens a path to Shotgun shells, armor, and more health.
Head back, and walk past the control panels to find another Imp. Blast it, and then switch to your Pistol to kill the Zombie around the corner. Move forward, and in the next room collect the armor and Shotgun shells. There's a Zombie in the corner waiting for you, and an Imp will enter when you grab the shells.
Head to the next hallway and another Imp will pop out from behind the corner - blast him, and keep moving. You'll run across another Zombie - headshots work wonders. You'll be back in the Underground Junction.
The door to your left is locked, so head downstairs and turn right to enter the Energy Stabilization Unit.
Pick up the PDA, which gives you clearance for that locked door, so back track with your Shotgun out - more Imps will pop up on your way. When you get through the door, kill the Z-SEC Zombie quickly and pick up the ammo and Health that's lying around. Use the computer terminal to unlock the elevator you need to use, as well as a weapons cache.
Back track to the previous room and kill the Z-SEC Zombie, then head left to wind up where you started. An Imp will drop down - send him down further with a Shotgun blast, then check the cabinet to your left for some ammo. A second Imp will come through the door you just used, so kill it, then open the elevator, shoot the Z-SEC Zombie, and finish the level.
