Eureka!

Eureka! is an achievement/trophy and final quest in Fallout: New Vegas if the Courier sides with the NCR.
==Synopsis==
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==
==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==
==Notes==
* 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 1.3.0.452.
* 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.
==Bugs==
==Gallery==
HooverDamAdv.png|
Category:Fallout: New Vegas quests
Category:Fallout: New Vegas NCR quests
Category:Fallout: New Vegas achievements and trophies
de:Heureka!
es:¡Eureka!
it:Eureka!
ru:Эврика!
uk:Еврика!
zh:找到了！