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Thanks for your support. I'll make sure that the NCR Emergency radio is up and running. Go kill those bastards.General Lee Oliver

Eureka! is an achievement/trophy and final quest in Fallout: New Vegas if the Courier sides with the NCR.


The Second Battle of Hoover Dam is erupting as Caesar's Legion storms the dam and attempts to snatch it from New California Republic control. The Courier fights alongside NCR forces to make it to the Legion's base of operations and either kill Legate Lanius or force the Legate to surrender.

Quick walkthrough

Quest: Eureka!
Talk to General Oliver.
(Optional) Flush the Legion invaders through the turbines.
Make your way through the power plant and across the dam.
Arrive at the Legion camp across the bridge, speak to Legate Lanius.
By passing a Speech or Barter check (100), the player can convince the Legate not to fight.
Otherwise, the player will have to defeat the Legate.
Once he is defeated, speak with General Oliver.
End Game

Detailed walkthrough

After completing You'll Know It When It Happens, at the very moment the Courier might choose to side with the NCR for the final battle (thus completing For the Republic, Part 2), the player character will be automatically taken from Col. Moore's office to General Oliver's compound, where the general will begin a briefing. The Courier is given the chance to wait, as this begins the end quest for the game. If the player character chooses to continue, after the briefing, Legion members attack the Hoover Dam and one will need to fight their way through the power plant rooms and head east toward their base, starting in power plant 04.

  • (Optional) Mike Lawson will speak to the Courier. If they wish to follow his suggestion and do the optional part which involves flushing the Legion invaders through the turbines, agree to his suggestion. To complete the optional part of the quest, follow the staircase immediately to the left in power plant 04 then across the room to enter power plant 03. The console is on the second floor of power plant 03, on the southern wall. Passing a Science check (65) allows the player character to use the terminal to engage the turbines. Completing this will require manual intervention; return to power plant 04 by the closest door which is right below the console. On the second floor on the east wall, from where the Courier reentered there is an exit to the Dam exterior. The manual release valve one needs to complete this part of the quest is along the river to the left between the broken retainer wall, just after the second sandbag wall. Return to power plant 03.

Proceed to power plant 02, then power plant 01, killing any Legion troops on the way. Climb the stairs on the left in power plant 01, then proceed north across the balcony. Follow the passage along the left, then go up the stairs, and exit via the elevator to the Hoover Dam visitor center. At this point, one will begin to notice assistance appearing from companions and factions the Courier has helped out along the way. Exit via the double doors on the east side to Hoover Dam.

Proceed to the north along the curved walkway above the dam. Enter the Hoover Dam checkpoint. From here, check the terminal; if the player character has a Science skill of 100 and a detonator, they may use the terminal to detonate one group of Legion soldiers (the blast is centered near the first tower). When one exits on the other side, they will encounter a squad of NCR Veteran Rangers. The commander will thank the Courier for their support and ask how to coordinate their assistance.

The player character can respond with several dialogue choices which lead to the following actions:

  • The Rangers snipe Legion soldiers;
  • The Rangers follow the Courier into battle;
  • The Rangers will pave the way for the player character (requires a Speech check of 85);
  • Rangers will fall back, providing no assistance.

After crossing the dam, head left along the bridge to the east, and continue, following the road. Enter the gate to the Legate's camp. Head east into the camp, following the path up the side of the ridge. There, one will encounter Legate Lanius. Note that with a Speech or Barter skill of 100, one can pass a series of skill checks, and avoid fighting him. The Legate is extremely challenging, and many Legionaries will come out and attack to aid him. If one passes all of the previous Speech checks and fails the last one, the player character will get another Speech challenge (85) which can convince the Legate to fight them one on one - all the other Legion troops will become non-hostile.

  • There is another tree of answers in dialogue with Lanius - the speech checks that suggest bluffing. This way does not require level 100 Speech (checks are 60-75-90-90). In the last Speech check, all three answers give the same result, but after it, one must choose the lie answer, and the Legate will flee.

After either killing the Legate or passing the Speech checks to end the fight peacefully, the Courier should notice the gate to the camp has closed. Head back to it. The gate will explode and the player character will meet with General Oliver.

Quest stages

10 The Legion is attacking Hoover Dam, the Legate's camp must be destroyed to protect the dam.
20 (Optional) Mike Lawson suggested flushing the Legionaries through the turbines to stop their invasion of the station.
30Quest finishedThe dam overflow has been diverted into the turbines, the Legionaries can no longer use them to access the power plant.


  • If any companions have been lost during the game, they will be teleported back to them for the battle.
  • If the Courier has enlisted the help of the Boomers and recovered the B-29 from Lake Mead, the bomber will be seen flying from the south over the dam when one exits the turbine building and will bomb the area in front of the player character. It will then fly off to the north towards Nellis.
  • Likewise, if the Courier has convinced the Boomers to assist them but have not recovered the bomber from the lake, Boomer howitzers from Nellis will provide artillery support by shelling the Legion.
  • If the player character has completed For Auld Lang Syne, the vertibird will appear after leaving the Hoover Dam checkpoint and the members of the Enclave remnants who agreed to help will assist with the battle on foot. If the Courier convinced them to assist the Legion, however, they will be hostile. This has since been fixed by patch
  • If the Enclave remnants participate in the battle, Cannibal Johnson will follow the Courier to the Legate's Camp and help them fight Lanius.
  • If the Brotherhood of Steel has agreed to help the NCR during the battle, two paladins will assist the player character in power plant 04. They will have T-45d power armor instead of the common T-51b. One paladin will follow the player character to the Legate's camp and help them fight Lanius.
  • If the Courier has convinced the Great Khans to aid the NCR, they will be outside helping the NCR. One will approach the Courier stating that they came just in time.
  • If the Followers of the Apocalypse agreed to be medics, the Courier will find Followers' first aid boxes scattered throughout the area.
  • If one has told Arcade Gannon to support the Remnants at Hoover Dam (at the end of the mission "For Auld Lang Syne") he will appear in his father's Tesla power armor fighting the Legion in the visitor center. He will stay in this area and will not leave.
  • When exiting the visitor center, the engineer who intended to kill President Kimball may still be outside in which he will take out his knife and rush to attack the NCR. One can search his body for the failsafe detonator.
  • Hearing Fantastic say "push the middle button to divert the intake" in his dialogue will allow the player to bypass the Science check of 65 needed to engage the turbines and flush out the invading Legionnaires. Fantastic can be found towards the back of power plant 01 if the player helped him during That Lucky Old Sun by sending the power to the Strip and McCarran without arming ARCHIMEDES and will be completely unphased by the battle occurring.

Behind the scenes

"Eureka" is the state motto of California. The word comes from the ancient Greek word heúrēka, translated to "I have found." There is a story of the famous Greek mathematician Archimedes, who shouted "Eureka!" upon making a great discovery and ran naked through the streets of Syracuse.


  • PCPC Playstation 3Playstation 3 Xbox 360Xbox 360 Occasionally, leaving power plant 1, one will randomly fail 'Don't Tread on the Bear!' and all NCR forces will go hostile. [verified]
  • Playstation 3Playstation 3 Xbox 360Xbox 360 If the Courier stays back until the Legate has killed both NCR Rangers, he will not talk to the player character on his own. That gives one the possibility for a sneak kill. [verified]
  • Playstation 3Playstation 3 Xbox 360Xbox 360 Sometimes the Legate will not register as dead and one cannot continue with the quest. POSSIBLE Fix: If one goes through the Speech checks and convinces him to fight the player character one-on-one, he will register as dead and one can continue the quest. Killing all the other Legion troops might fix this problem as well. [verified]
  • PCPC Using setstage 00136166 100 spawned none of the needed minions to continue the mission regardless of the fact that the player character has progressed and done all available side missions and fought through to the Legate's camp (as the previous mission had bugged). [verified]
  • PCPC If the final missions have bugged out while trying to help the NCR (as happens if one completes Wild Card: Side Bets before For The Republic Part 2), one can use setstage "00136166" 100. The Courier can then fight their way to the Legate's camp but Legate Lanius won't appear. One can then use setstage "00133075" 20 and General Lee will appear as they go to leave the Legate's camp, thereby starting the endgame sequence. [verified]
  • Playstation 3Playstation 3 The Legate has been known to flee once the two NCR Rangers appear, he will go out of the main gate, and cannot be followed as the gate will have no sense of interaction. [verified]
  • Xbox 360Xbox 360 There is a glitch where the player character will be able to fast travel out of the dam and camp, but can not reenter because the area is sealed off. Making it impossible to finish the quest. SOLUTION: a weak solution to this problem: If one wants to fast travel, they must enter an area that they can not fast travel from (house, building, tent, etc.) and exit it again. Immediately upon loading outside, one must press the Pip-Boy button and they will be able to fast travel, but requires that one must repeat the process again after arriving at the next destination. This allows the player character to continue the quest. [verified]
  • Playstation 3Playstation 3 Xbox 360Xbox 360 It is possible for a companion to become effectively trapped in Oliver's compound. this is due to the fact it becomes labeled "locked requires key". This means the trapped companion cannot follow. For some odd reason, they will not teleport as usual when you go through a loading screen door. This was experienced with Veronica Santangelo and Rex as a companion. Rex followed as normal. [verified]
  • Playstation 3Playstation 3 Xbox 360Xbox 360 Even after one kills Legate Lanius the quest marker will remain on him until all of Caesar's Legion in the area are dead. This can sometimes break the quest as the Legion in the area is effectively stored in an unreachable area to the left of the main building where the Courier encounters the Legate. This can be fixed via explosives such as rockets to kill them via blast radius. [verified]
  • Playstation 3Playstation 3 It is possible for the player character to fast travel when this quest is in progress by simply going through the Hoover Dam checkpoint and straight after one comes out quickly go to the Pip-Boy and fast travel. WARNING after doing this one will have to use that same method if they want to fast travel again. [verified]
  • Xbox 360Xbox 360 It is possible that, while fighting the Legate, a glitch may cause him to suddenly "fly" straight up into the air almost beyond the point of visibility before plummeting back down to the ground, killing him on impact, thus winning the fight and the game. (This glitch was only observed after many, many failed attempts at killing him and restarting from the last save-point.) [verified]
  • Playstation 3Playstation 3 Xbox 360Xbox 360 If the player character is using weapons with high rates of fire, being around others with high ROF weapons may cause severe frame rate lag or freezes. [verified]
  • Xbox 360Xbox 360 Sometimes, if one has completed Oh My Papa for the NCR by assassinating Papa Khan, the Great Khans that appear to assist will be invisible and attempting to target them in V.A.T.S. will cause the game to freeze. [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 · Poor Meat Never Makes Good Soup · 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
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