This is a walkthrough for the You'll Know it When it Happens main quest in Fallout New Vegas (FNV). See a detailed walkthrough of You'll Know it When it Happens, list of objectives, how to unlock, best choices, rewards, as well as useful tips for completing You'll Know it When it Happens.

You'll Know it When it Happens Walkthrough

List of Objectives
1	Report to Ranger Grant at Hoover Dam
2	(Optional) Investigate For Clues
3	Meet Ranger Grant Outside
4	Stop the Assassination Attempts ┣ Bomb on the Aircraft ┣ Sniper at the Tower ┗ Legion Disguised as Engineer Rewards: 1000 XP, NCR Infamy

Note: A denotes a point where you can end the quest.

Report to Ranger Grant at Hoover Dam

Find Ranger Grant in the Visitor Center of the Hoover Dam. Interact with him several times until it is time for Kimball's speech.

If your reputation with the NCR is less than liked, you will not be allowed to draw your weapon which can make this quest more difficult.

Investigate For Clues (Optional)

You can do this objective if you want to know more about the assassination attempts. However, there will be no quest markers for the steps in this objective, so you have to find the clues on your own. Additionally, this objective yields no rewards.

Clues
1	Talk to Allison on the 2nd floor of the Visitor Center and you'll learn about a missing engineer.
2	Check the supply closet underneath the stairs to find blood. You will need 6 Perception to examine it and learn that an engineer was killed here.
3	If you have 50 Science, hack the terminal in the Visitor Center to learn of an unauthorized access ID.

Meet Ranger Grant Outside

Interact with Ranger Grant outside. You will be given the chance to explore the area to investigate further and look for clues regarding any assassination attempts. Once you're ready, report to Ranger Grant, and the president will start arriving via aircraft.

Stop the Assassination Attempts

There will be 3 possible assassination attempts and there are multiple ways to thwart each. After thwarting one of the attempts, you can report to Ranger Grant immediately and he will cut the president's speech.

Whether the speech was finished or not, as long as the president survives, the quest is completed. But if the president dies in any way, the quest is failed.

Bomb on the Aircraft

Before the aircraft lands, you will notice an engineer waiting on the landing pad who will interact with the plane, sneakily planting a bomb that he will detonate when the president returns to the aircraft to leave.

Sniper at the Tower

If you watch the tower behind the stage, you might catch that a second person will appear to throw the other off the tower. If you miss this event, you can also head to the tower to find the body of the fallen trooper on the ground. Near the end of the president's speech, the assassin will use a sniper to shoot and kill the president.

Legion Disguised as Engineer

If the engineer witnesses the player diffusing the bomb they planted on the aircraft, that same engineer will attempt to stab the president with a knife.

How to Unlock You'll Know it When it Happens

Depends on Major Faction Progress

You'll Know it When it Happens will be unlocked during specific main quests while progressing through the story of 3 of the 4 major factions.

You'll Know it When it Happens Rewards

Fallout New Vegas Related Guides

Complete Story Walkthrough

List of Neutral Main Quests

List of Yes Man Main Quests

List of NCR Main Quests

List of Mr. House Main Quests

List of Caesar's Legion Main Quests