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The Vault - Fallout Wiki
You'll Know It When It Happens
FNV You Will See It Coming.jpg
You'll Know it When it Happens.png
Quest data
LocationHoover Dam
Given ByGrant
Yes Man
Mr. House
Reward1000 XP
NCR fame
AchievementYou'll Know It When It Happens
Xbox Live gamerscoreIcon gamerscore.png20PlayStation 3 trophyIcon ps3trophy.pngBronze
Editor ID?
Base ID00131f08
Related quests
For the Republic, Part 2 or
The House Always Wins, Part V or
Wild Card: Finishing Touches
leads to:
Eureka! or
All or Nothing or
No Gods, No Masters

You'll Know It When It Happens is a main quest in Fallout: New Vegas.


Aaron Kimball, President of the New California Republic is visiting Hoover Dam to improve morale among his troops. Naturally, the NCR seeks to keep their President safe while he's in a war zone and their political leader, but Mr. House wants Kimball alive for a different reason: he posits that as long as Kimball remains alive, he remains a scapegoat for House, meaning the NCR public will blame him, and not New Vegas, for the NCR defeat at Hoover Dam.


  1. Speak to NCR Ranger Grant at Hoover Dam to make preparations for Kimball's arrival.
  2. Conduct a security sweep throughout the dam
    1. Talk to Allison Valentine on the second floor of the visitor center. Her engineer friend has gone missing; a blood stain can be found in the supply closet on the first floor and requires a Perception of 6 to notice.
    2. Hack the computer terminal in the visitor center (Science 50 required) to reveal that the terminal was accessed with authorization.
    3. If Craig Boone a companion, he will remark that if he were a sniper, he would shoot from the ridge left of the road heading north, the intake tower behind the stage or the roof of the visitor's center.
  3. Once you have conducted your search, return to Ranger Grant.
  4. Prevent the three different assassination attemps:
    1. A sniper, dressed as an NCR Ranger, will appear atop the intake tower behind the stage set up for the speech;
    2. A bomb is placed on Bear Force One by an engineer;
    3. A Legion soldier, disguised as an engineer, will run up to the President and try to assassinate him with a knife. If Ranger Grant is told of either of the two attempts detailed above, this is avoided.
  5. Report your findings to Ranger Grant.


  • It is possible to automatically and accidentally fail this quest before you take it. After you load Yes Man onto Mr. House's computer, speak to him and he will tell you that there is a chance of the President being assassinated. Strangely enough, there is no option to save the president later and any dialog box you choose will automatically cause you to fail the quest. If this occurs, revert to your last save and complete (For the Republic, Part 2) before you continue on with any quest from Yes Man.
  • You must be at least accepted by the NCR to do this quest.
  • If you fail the quest by letting the President die, you are still given the next quest (Eureka!) anyway unless you fail 'Don't tread on the bear!'.
  • The official Prima Games strategy guide does not account for the third assassination attempt - wherein a Legion operative disguised as an NCR engineer rushes the stage with a knife. You will not be able to hear President Kimball finish his speech if you report your findings to Ranger Grant early.
  • If you deal with all three assassination attempts without informing Grant and without interrupting the speech, President Kimball will finish his speech, say thank you, and then continue talking, making some colorful remarks without realizing that the microphone is still on. What he says is a spoof of real presidents who have made the same mistake.
  • It is also possible to skip the entire quest yet still complete it. If you take out your weapon as the president's vertibird lands while standing near Ranger Grant, then put away your weapon, the note that you should return to Colonel Moore to let her know that the President has safely left will appear.
  • Stepping into the backstage area will cause everyone turn hostile to you. You will be warned first.

Quest stages

1 Report to Ranger Grant.
2 Meet Ranger Grant on the Observation Deck.
4 Keep an eye on sniper locations.
5 Protect President Kimball.
6Quest finishedReport your findings to Ranger Grant.

Behind the scenes

  • After killing the Legion sniper on the guard post and using the radio to report to Grant, one of the dialog options ("We're all fine here, thank you. How are you?"[1]) is a cultural reference to dialogue said by Han Solo from Star Wars Episode IV: A New Hope when he and Luke Skywalker are saving Princess Leia from the Death Star.
  • A majority of this quest was implemented by Charlie Staples.[2]


  • PCIcon pc.png PlayStation 3Icon ps3.png Xbox 360Icon xbox360.png If you start Wild Card: Finishing Touch after starting this quest, you won't be able to talk to Ranger Grant (only one dialog option - Goodbye) and thus unable to start the event. Your only option is to finish Finishing Touch and let the President die.
    • This bug can be fixed in the console. Select Ranger Grant in the console or type prid 0013721f and hit enter. Then type disable hit enter, and type enable. He will be reset and start talking to your character. It may be required to disable and wait several hours then re-enter prid 0013721f and enable.
    • If you approach him from behind also seems to fix this bug, as it makes him start the conversation.
  • PCIcon pc.png PlayStation 3Icon ps3.png Xbox 360Icon xbox360.png After killing the sniper, report back to Ranger Grant. His first dialogue will be normal but his second sounds like it's coming through an intercom.
  • PCIcon pc.png PlayStation 3Icon ps3.png You can automatically fail the quest if you take the ladder down to the shore and swim to the opposite end of the Hoover Dam.
  • PlayStation 3Icon ps3.png Xbox 360Icon xbox360.png If you disarm the bomb on the vertibird and then immediately run to the tower where the sniper spawns, climbing the ladder to the top of the tower may initiate the following sequence. When you reach the top, you will hear the scream of someone falling, but the Ranger sniper is still there alone and fine. If you wait through the speech on the tower with the Ranger sniper, nothing happens until the very end of the speech where a shot will ring out, President Kimball will disappear, the Ranger sniper on the tower (next to you) will disappear, and you will fail the quest (the only dialogue option when talking to Colonel Moore afterward is to tell her that the President was killed by a sniper).
  • PlayStation 3Icon ps3.png Xbox 360Icon xbox360.png It is possible that Kimball's Vertibird may land and then suddenly take off. After this, the quest will be rendered complete without you having to stop any assassination attempts.
  • PlayStation 3Icon ps3.png Xbox 360Icon xbox360.png When the Vertibird is flying to come over to the base to land. Press X and you'll complete the quest without having to protect him.
  • PCIcon pc.png Sometimes, even though you start the quest by speaking with Ranger Grant, after you investigate the closet and check the terminal, going up onto the observation deck will not trigger the Vertibird landing and Ranger Grant will not initiate dialog any more.
  • PCIcon pc.png After initiating the dialog where Ranger Grant tells you to get some rest before the President arrives, the game may crash after fading out.
  • PlayStation 3Icon ps3.png Though there are three assassination attempts, not all of them may be triggered during the quest. The bomb on the Vertibird will usually go off unless you deal with it, but the sniper and assassin in the crowd may not act.
  • PlayStation 3Icon ps3.png If President Kimball finishes his speech and successfully makes his way back up to his vertibird, he may start walking endlessly against the ledge of the roof of the visitor center away from the vertibird, and never leave. To fix this, talk to Ranger Grant regarding the bomb or the sniper, and this will initiate the escape sequence for President Kimball, forcing him to depart in his vertibird.
  • Xbox 360Icon xbox360.png When you try to pickpocket the engineer and take his detonator and keys, without disabling the bomb in the President's vertibird, it still would explode. even after you protect the President from the sniper and the assassin. the trick of this glitch is to kill the engineer right after the vertibird landed, causing the President to flee safely before he is able to start his speech.
  • Xbox 360Icon xbox360.png When you start the quest talk to ranger grant outside tell him you are ready then run up to the tower behind the stage climb the ladder then climb down and it should say quest completed.
  • Xbox 360Icon xbox360.png It is possible that when climbing the ladder to the tower with the sniper assassin while having ED-E as a companion, that all NCR troops will become hostile to ED-E. Easily fixed by telling ED-E to go back to the Lucky 38 with the latest patch since it will despawn him on the spot. This also forced the rangers to evacuate the President and complete the mission.


  1. The Courier: "We're all fine here, thank you. How are you?"
    Grant: "Quit goofing off and clear the channel. I'll be damned if the President dies on my watch because you were screwing around."
    (Grant's dialogue (Fallout: New Vegas))
  2. Joshua Sawyer on Formspring: "Who wrote You'll Know It When It Happens/Arizona Killer? Running security and checking for clues was great, especially Boone's comments about possible sniper locations"
    "Charlie Staples handled the majority of implementation for those two quests."
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 · Access Powers · All Fired Up! · 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 · Flogging a Dead Corpse · Friend of the Followers · Getting a Leg Up from Andy · 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 · Not Worth a Hill of Corn and Beans · Of Boomers and Education · 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 · Proper Burial · Razzle Dazzle! · Reach for the Sky, Mister! · Rest and Resupply · Ringo's Caravan Rules · Rotface's Loose Lips · The Screams of Brahmin · Silus Treatment · Short-Term Treatment · Smooth-Talking Criminal · Strategic Nuclear Moose · Straus Calls · Strip Search · Saving (or Savaging) Sergeant Teddy · Stocking Up · Suits You, Sarah · A Team of Moronic Mercenaries · Team Spirit · The Thorn Mayhem · 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 (I, II, III, IV) · Wind-Brahmin Wrangler · You Gotta Break Out a Few Eggs · You Make Me Feel Like a Woman
Cut contentIcon cut.png Cut questsAuto-Inject Quest · Bright and Shiny · Chip Provenance · Debug Topics · Jailhouse Rock · Meat of Champions (quest) · TempMan · The Thorn Mayhem · Underpass Water Purifier · Viva Las Vegas! · Welcome to Fabulous New Vegas
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