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Welcome to the Big Empty is the first main quest in the Fallout: New Vegas add-on Old World Blues.

Quick walkthrough[]

Main Quest: Welcome to the Big Empty 
Arrive at The Sink balcony
Take the elevator to The Think Tank
Agree to help the doctors. 
Reward: Variable XP
If skill checks are passed: Various ammunition, a sonic emitter, a K9000 cyberdog gun, and caps 
Leads to: All My Friends Have Off Switches, X-2: Strange Transmissions!, X-8: High School Horror!, X-13: Attack of the Infiltrator!, Sonic Emitter Upgrade 

Detailed walkthrough[]

Upon being teleported to Big MT, the Courier awakens on the balcony of the Sink, facing outwards towards the expanse of the massive crater beyond a protective forcefield. A message appears indicating they feel strangely heavier. The way to answers lies through the door behind into the Sink. The inside of the Sink is homey, but most of the appliances in there won't work, instead reporting that they lack the required personality modules. In the master bedroom, on a shelf to the right of the bed is a pair of mad scientist scrubs. The way forward is through the only unlocked door leading into the Think Tank.

Get ready to talk. A lot! Before entering the Think Tank you might want to prep for the initial conversation and follow-up chats with each doctor. Additional XP and loot options unlock at these thresholds (see below for more details on each):

  • Perception: 7, 8
  • Intelligence: 7, 9
  • Barter: 25, 50, 75, 90
  • Energy Weapons: 50
  • Guns: 50
  • Speech: 50, 55, 65
  • Science: 25, 35, 70, 75
  • Medicine: 50, 75

After entering, the player character gets a message saying a strange feeling of pacifism affects them, preventing them from drawing a weapon (Unarmed fists included) in the Think Tank. Proceed forward into the larger dome and approach the five multi-colored robots, with the one in front, Dr. Klein, speaking for the group, also called the Think Tank. Through conversation, the player character learns that the earlier heavy feeling is because the Think Tank performed surgery on them and removed their brain, their heart, and their spine, replacing them with advanced technology in the process. The brain in particular was lost by them and presumed stolen by their nemesis, Dr. Mobius who then broadcasts a threatening message to the Think Tank. Klein charges the player character with gathering three technologies to help defeat Mobius in his Forbidden Zone: the sonic emitter, the stealth suit Mk II, and the X-2 antenna; the former is already in the Think Tank's possession and soon after given to the Courier, but it still requires an upgrade that can penetrate Big MT forcefields to complete the puzzle.

After agreeing to stop Mobius, the Think Tank gifts the player character with access to The Sink as their personal quarters while in Big MT along with use of the Sink Central Intelligence Unit as a vendor to trade for needed supplies.

Through various conversation options, the Courier will be able to talk the doctors into giving various items for use in their quest. The "Revelation" audio file is automatically loaded in the sonic emitter upon receiving it and with 50 Energy Weapons, extra SECs for it will be given. With 50 Guns, the scientists offer up a K9000 cyberdog gun and with a further check of 75, extra .357 Magnum rounds for it will be given. Other potential gifts include supplies of doctor's bags, stimpaks, caps, and various skill magazines through Barter checks of 25, 50, 75, and 90 respectively.

Immediately after the main conversation, you can quickly talk to each doctor to take advantage of any temporary boosters still active:

  • Dr Dala:
    • Perception: 8
  • Dr O:
    • Do you have another name? (non-repeatable)
      • Speech: 65, then Intelligence: 7, then Intelligence: 9
      • Speech: 50
  • Dr 8:
    • First approach:
      • Science: 75 or Perception: 7, then Science: 75
    • Second approach:
      • Speech: 50
  • Dr Klein:
    • Did you retrieve the tech?
      • Science: 70 or Speech: 55
    • Who is Dr Mobius? (ask twice)
      • Science: 25
      • Medicine: 50
    • You Said Dr Mobius might have my brain?
      • Science: 35 or Medicine: 75

Quest stages[]

10 Find out where the hell you are.
20 Speak to your... captors.
30 Get the X-2 antenna brain array thing, the sonic-soundwave-projecto-emitter spine thing... and the sneaky heart suit.
40 Correction: They have the sonic... projecto... emitter gun. They need a new frequency for it.
50 Correction: So get the X-2 antenna brain array thing... the new frequency for the sonic emitter, and the sneaky heart suit.
60 Correction: Wait, there's another optional sonic emitter frequency that disables Force Fields that's not the frequency they need...? Ugh, forget it.
70Quest finishedClosing out these entry logs, clearing the utility partition.


  • The Think Tank area cannot be exited until the quest is finished.
  • If no dialogue is skipped, this sequence can take up to 30 minutes, depending on what the player says.
    • There is a dialogue option to skip past the first part of the sequence, learning about the surgery and questions from the doctors by pointing out that the large screen behind them has a message, proceeding straight to Mobius' threat and the technology quests triggering.
  • The Brainless, Heartless and Spineless perks are added the moment one appears on the Sink balcony. The pop-ups telling the player that the perks were added will not appear until the dialogue with the doctors, but the perks can be viewed in the Pip-Boy menu and will be fully functional.


  • Playstation 3Playstation 3Playstation 3 Xbox 360Xbox 360 Upon spawning on The Sink balcony at the beginning of the quest, the game may freeze. Restarting the system, and reloading the autosave will take the player right back to The Sink balcony. There is very strong, almost stand-still lag. Resetting the PS3 will usually fix this problem. [verified]
    • Xbox 360Xbox 360 One way to avoid this is to quickly turn to face south while the screen is still black and try to activate the door into the Sink before the player character's vision returns, bypassing the bug and allowing one to then walk back out onto the balcony without further issue.
  • Playstation 3Playstation 3Playstation 3 The lag does persist, but only if the player returns to or remains at the balcony. Reloading the save and/or restarting PS3 does not seem to help. There is always stand-still lag, even when trying to look around. Entering The Sink will usually fix this issue. [verified]
  • PCPC Playstation 3Playstation 3Playstation 3 Avoiding the lag issues mentioned above all-together can be achieved by saving and reloading the game immediately prior to teleporting via the downed satellite.[verified]


Main quests
Act 1Ain't That a Kick in the Head · Back in the Saddle · By a Campfire on the Trail · They Went That-a-Way · Ring-a-Ding-Ding!
Act 2Wild Card (Wild Card: Ace in the Hole, Change in Management, You and What Army?, Side Bets, Finishing Touches) · The House Always Wins (I, II, III, IV, V, VI, VII, VIII) · Render Unto Caesar · Et Tumor, Brute? · Things That Go Boom · Kings' Gambit · For the Republic, Part 2 · You'll Know It When It Happens/Arizona Killer
Act 3No Gods, No Masters · All or Nothing · Veni, Vidi, Vici · Eureka!
Side quests
New California RepublicAnywhere I Wander · Back in Your Own Backyard · Bitter Springs Infirmary Blues · Boulder City Showdown · Can You Find it in Your Heart? · Climb Ev'ry Mountain · Don't Tread on the Bear! · Emergency Radio · Eye for an Eye · Flags of Our Foul-Ups · Hard Luck Blues · I Don't Hurt Anymore · I Put a Spell on You · Keep Your Eyes on the Prize · Medical Mystery · No, Not Much · Pressing Matters · Restoring Hope · Return to Sender · That Lucky Old Sun · The White Wash · There Stands the Grass · Three-Card Bounty · We Will All Go Together · You Can Depend on Me
Caesar's LegionBeware the Wrath of Caesar! · Caesar's Favor · Caesar's Foe · Caesar's Hire · Cold, Cold Heart · I Hear You Knocking · The Finger of Suspicion · We Are Legion
The StripBeyond the Beef · Bye Bye Love · Classic Inspiration · How Little We Know · Pheeble Will · Talent Pool · The House Has Gone Bust! · The Moon Comes Over the Tower
Freeside & Outer VegasBirds of a Feather · Bleed Me Dry · Debt Collector · G.I. Blues · High Times · Someone to Watch Over Me · The Coyotes · Wang Dang Atomic Tango
BoomersAnt Misbehavin' · Sunshine Boogie · Volare! · Young Hearts
Great KhansAba Daba Honeymoon · Cry Me a River · Don't Make a Beggar of Me · Oh My Papa
Powder GangBooted · I Fought the Law · Run Goodsprings Run · Why Can't We Be Friends?
Brotherhood of SteelEyesight to the Blind · Still in the Dark · Tend to Your Business
OtherCome Fly With Me · Crazy, Crazy, Crazy · Ghost Town Gunfight · Guess Who I Saw Today · Left My Heart · My Kind of Town · The Legend of the Star and A Valuable Lesson · Unfriendly Persuasion · Wheel of Fortune
Companion questsED-E My Love · For Auld Lang Syne · Heartache by the Number · I Could Make You Care · I Forgot to Remember to Forget · Nothin' But a Hound Dog · One for My Baby
Unmarked questsA Bit of Slap and Tickle · A Final Plan for Esteban · Access Powers · All Fired Up! · An Ear to the Ground · Andy and Charlie · Arachnophobia · Arizona Scavenger · Barton the Fink · Bear Necessities · Big Winner (Atomic Wrangler, The Gomorrah, The Tops, Ultra-Luxe, Vikki & Vance) · Bounty Killer (I, II) · Brotherhood Bond (I, II) · Caching in at the Cove · Cajoling a Cudgel · Claws Mended · Claws Out · Dealing with Contreras · Defacing the Humble Stone · Democracy Inaction · Don't Poke at the Bear! · Eddie's Emissary · Exhumin' Nature · Fight Night · Flogging a Dead Corpse · Friend of the Followers · Gland for Some Home Cooking · Harder, Better, Faster, Stronger · Hat's Entertainment · Help for Halford · Hidden Valley computer virus · Highway to the Danger Zone (I, II) · Honorary Rocketeer · I Love Bananas · Iron and Stealing · Keith's Caravan Charade · Laurifer Gladiator · Lenk's Bad Debts · Lily and Leo · Long-Term Care · Malleable Mini Boomer Minds · Maud's Muggers · Meeting an Equal · Missing a Few Missiles · Most Wanted · Not Worth a Hill of Corn and Beans · Old School Ghoul · A Pair of Dead Desperados (I, II) · Papers, Please · Pistol Packing · Playing on the Old Joana · Powder to the People · Power to the People · Razzle Dazzle! · Reach for the Sky, Mister! · Rest and Resupply · Ringo's Caravan Rules · Rotface's Loose Lips · Saving (or Savaging) Sergeant Teddy · The Screams of Brahmin · Silus Treatment · Short-Term Treatment · Smooth-Talking Criminal · The Star Showdown · Strategic Nuclear Moose · Straus Calls · Strip Search · Suits You, Sarah · Tags of Our Fallen · A Team of Moronic Mercenaries · Thought for the Day · Tourist Traipse · Trudy's Radio Repair · A Trusted Aide · Useless Baubles or Fancy Trinkets? · We Must Stop Beating Like This · We Must Stop Meeting Like This · Wind-Brahmin Wrangler · You Gotta Break Out a Few Eggs · You Make Me Feel Like a Woman
Add-on quests
Dead MoneySierra Madre Grand Opening! · Find Collars (8: "Dog", 12: Christine, 14: Dean Domino) · Fires in the Sky · Strike Up the Band · Mixed Signals · Trigger the Gala Event · Put the Beast Down · Last Luxuries · Curtain Call at the Tampico · Heist of the Centuries · Big Winner, Sierra Madre · Return to the FountainCut content
Honest HeartsA Family Affair · Arrival at Zion · Bighorners of the Eastern Virgin · Chaos in Zion · Civilized Man's Burden · Crush the White Legs · Deliverer of Sorrows  · Departing Paradise · Flight from Zion · Gathering Storms · Gone Fishin' · Happy Trails Expedition · Prisoners of War · Retake the Bridge · River Monsters · Rite of Passage · Roadside Attraction · Sanctity of the Dead · The Advance Scouts  · The Treacherous Road · The Grand Staircase · Tourist Trap
Old World BluesAll My Friends Have Off Switches · A Brain's Best Friend · Coming Out of Her Shell · Field Research · He Came... And Went · Influencing People · Midnight Science Fiction Feature! · Old World Blues · On the Same Wavelength · Picking Your Brains · Project X-13 · Sonic Emitter Upgrade · Welcome to the Big Empty · What's in a Name? · When Visitors Attack! · X-2: Strange Transmissions! · X-8 Data Retrieval Test · X-8: High School Horror! · X-13: Attack of the Infiltrator!
Lonesome RoadThe Reunion · The Silo · The Job · The Launch · The Tunnelers · The Divide · The Courier · The End · The Apocalypse