- The Gearheads control electricity around here, and I want to end their stranglehold on my town.
- Word on the street is the Gearheads have combined Plutonium and Feltrite. If we could get our hands on that, then our power problems would be over. Trouble is, they got that stuff all locked up in the Bank Vault above us. So I need you to go and get it for me. Here's a key to the Management Office. You can find the office on the second floor in the back of the town.
- Bring me that Plutonium Feltrite and maybe it'll secure your place around here.
- Search the Gearhead's Vault for the Plutonium Feltrite
- Head to the Management Office upstairs in Subway Town
- Locate the Plutonium Feltrite in the old bank Vault
- Take the Plutonium Feltrite to Redstone
- Tip: Gearheads are rather tough enemies. They are well armored, deploy Sentry Bots a lot and love grenades, so consider equipping appropriately. Stock up on armor piercing and heavy ammo, some Bandages, and don't forget about Wingsticks, RC Bomb Cars and/or Sentry Bots / Sentry Turrets. Buy the heavy upgrade for your armor in "Jani's Supplies", if you haven't already. Also, read the Doom room article.
When you're given the quest, Mayor Redstone will hand you the Management Office key. The office is near the Strum minigame on the top floor of Subway Town. Open the door and head down the corridor to access the Gearhead Vault. Once inside, turn tight and take a look at the closest door — that's the entrance to the secret Doom room, although it's closed for now.
Head forward to pick up a suitcase and an Oil Can to the right of the stairs and use a Lock Grinder on the locked door nearby for some ingredients and other loot. Once done, head out of the room and carefully head up the stairs. There is a hanging booby trap in front of you that looks like a small World War II German naval contact mine, and you don't want this thing to explode nearby.
The first main room is littered with car wrecks providing a lot of cover and contains a lot of resistance, including two Sentry Bots and a Gearhead Minigun, so be prepared. Note that the Miniguns don't often have great loot, so feel free to explode them however you see fit. Once you've cleared the area, there's lots to pick up, so look around carefully.
Head up the slope, pick up a can, continue around the corner to snag the Advanced Sentry card from the white car and some Buckshot a little further, and then proceed up the slope where a Gearhead Club will charge you, while a couple of shooters pepper you from cover. Clear out the bar area — lots of loot there, and then head up the ladder.
Up top, you'll meet some more Clubs, and a lot of shooters. Advance through this area (try not to shoot the fragile Beer Bottles) then loop back and grab all the loot. Don't forget to empty the vending machines as well; also, you can loot the trash can sitting next to the red Kola Kong. Continue around until you get to a valve on the far side, which you need to activate. This will switch off the flames, so jump in the lift and head through the newly opened route.
Again, expect a lot of resistance, but note that there's water around, and some Electro Bolts on the counter in front of you. As you clear the room, you'll meet a Minigun so be prepared, and once again, watch out for Beer Bottles available in the area. When you're done, don't forget the eight ATMs, a few HE Grenades, and the Gearhead Shotgun card at the back right.
Heading into the next room, you'll find the computers used to access the secret Doom room, but be careful because as you advance, flames will spout up and two Miniguns will attack. The grenades from the previous room will come in handy here, as well as Pop Rockets if you have some. Once the area is clear, find seven keyboards that are located near corresponding computer monitors and activate them. This will open the door to the secret room back at the beginning of the level, and you can enter the room after you finish this mission.
Head out, and up the stairs. Watch out for the barrel and a Club as well as the spinning blades in the next room. You can "encourage" the enemies that will appear later to walk into them though. That would be a good plan. Walk through only when they're not moving. Head through to the big main room and grab the broken Feltrite power cell, and don't miss the gold bars in an open drawer to the left that will bring you $100 immediately.
Once you grab the cell, a heavy with a flamethrower will come into the room. Shoot the tank on his back (you can see it over his shoulder) to explode him — again, they never seem to carry good loot — and then it's back to the blade room where you have a couple of regular troops to deal with. Once you get them, run to their bodies as the wall explodes, and get out of sight. If the timing is right, the Minigun who arrives is pretty stupid and will walk straight into the blades; otherwise, you'll have to take him down. Cross back through the blade area and enter this new hole in the wall.
Just in here on the left is the Gearhead Jet card, but that's about the only good news. There's a handful of troops with a mix of weapons, including one with a Rocket Launcher and a good aim, so try to stay out of trouble. Once they're dealt with, head down the stairs, take a left, and activate the valve to switch off the flames. There will be two Gearhead Jets past the ATMs, so have some fun and try to shoot the tanks out.
Continue back to the management office entrance, and don't forget about the Doom room Easter egg, if you've set that up. Once finished sightseeing, head back to Redstone, and you're all done.
- Completing the Gearhead Vault in the Campaign gets you the Achievement/Trophy "Vault Assault".
- Every Collector Card picked up counts towards getting the Achievement/Trophy "Gotta Have 'em All".
- There is a Doom Marine Bobblehead in the secret Doom room identical to the one in Dan Hagar's Dune Buster. You saw the bobblehead on the way to the Hagar Settlement during the Prologue.
Here is a fun shot, and a few tricky ones. See what you can do.