When you reach the Citadel. Owyn Lyons will be briefing his daughter Sarah and her Lyons' Pride. preparing for an assault on the purifier. After informing them of the situation, Sarah's squad is mobilized and Scribe Rothchild will activate Liberty Prime. after some initial reluctance.
Prime is launched despite the objections of Scribe Rothchild, who demands it not be used and declares ". it's not ready for field tests, let alone live fire situations - the weapons haven't been calibrated, the navigation detection system is offline. " Despite his warnings, Prime is launched and used without any malfunctions.
To begin the advance on the Jefferson Memorial. the player must speak with Sarah Lyons. Note that once the order to attack has been given the green light, all functions and services in the Citadel will cease. All non-player characters will spout encouraging phrases such as, "The purifier is as good as ours!" if spoken to. If the player has anything to do in the Citadel, he or she must complete their task before commencing the attack.
Following the order to attack, Liberty Prime will be hoisted out of the Citadel on a crane and the Lyons' Pride will follow it, as should the player. Prime actually crashes his leg on the wall in the Bailey on the crane, however it does not heavily damage him. Once outside the Citadel, Prime will begin stomping his way to the fallen bridge, killing everything in its path. Liberty Prime will take down the photonic resonance barriers set up by the Enclave by walking into them.
Once on the bridge, the Enclave will desperately throw everything it has at the Brotherhood's machine: soldiers, Vertibirds. and artillery. Their efforts are entirely for naught, and Liberty Prime will annihilate everything thrown at it. It is scripted to miss a few of the troops in the confusion, however. Liberty Prime will destroy any incoming Vertibirds, so the player only needs to worry about ground troops. Targeting the ground troops can be a pain due to all the screen-shaking occurring (Mini-Nuke and artillery shell explosions) so V.A.T.S. is a good alternative to freehand aiming. The Lyons' Pride soldiers will also do a fair job of mopping them up. However, keeping all of them alive will be difficult. The artillery shells tend to arc in from both sides of the bridge, but are notoriously inaccurate. Exploding vehicles are very deadly, so the player should find cover either behind Liberty Prime, or behind previously exploded vehicles. The player may feel intimidated by the concussive blasts, but will rarely take damage from them.
Liberty Prime cannot be stopped, and will inexorably clear a bloody path to the Memorial. The player and Lyons' Pride can come under attack from targets on a catwalk between buildings after clearing the bridge from the Citadel. It is possible to hustle to the near building, enter the door, run up several flights of stairs, and emerge beside the enemies on the catwalk, but this is a very impractical way of doing the job: a ranged weapon will work just fine. Melee and Unarmed characters can simply let the Lyons' Pride finish up these troops, but they take quite a while. Either way, Liberty Prime will continue carving his way though the resistance, past the irradiated metro and onwards to a second bridge. At the end is where Liberty Prime stops, and holds his position along with the rest of the Lyons' Pride while Sarah Lyons and the player dash inside the Jefferson Memorial through the Gift Shop. Note that, if you hesitate, a significant force of Enclave soldiers will be deployed nearby, either from the bridge or the catwalks around the memorial. Liberty Prime will destroy them.
There is light resistance inside the Gift Shop, usually three or four Enclave soldiers. The player as well as Lyons should be able to clear the room. Grenades work well in these quarters.
After entering the Rotunda, the doors seal shut. Not locked, nor pickable, completely sealed. There is no leaving the Rotunda after entering it. Colonel Autumn is waiting for the player and Lyons in the Rotunda, and locks the player in dialogue. He seems unsurprised at the player's arrival at the purifier. The player has two choices at this point:
- Talk Colonel Autumn out of attacking. This is a rather difficult speech check, even with 100 Speech (around a 50/50 chance assuming 5 Charisma). After conceding defeat, he will leave the player to their fate. After this, Sarah Lyons will give a short remark on the player's decision, depending on his or her Karma. (NOTE: If Raven Rock was destroyed in the last quest. you will have the option to use an easier speech check.)
- Fight Colonel Autumn. The Colonel isn't terribly hard to defeat, but his bodyguards are tougher: They are two standard Enclave soldiers, at least one of whom is usually equipped with Tesla armor. It is possible to attack the Colonel and kill him before the dialog begins, though the soldiers are still hostile.
After resolving the situation and heading up the stairs to the control room, a panicked Dr. Li will key the intercom: Project Purity has sustained severe damage in the battle, and has become overloaded. It will soon self-destruct if the purifier isn't finally started, but the control room has become heavily irradiated.
NOTE: Those with Broken Steel installed have additional options in completing this quest, as detailed in the second decision option.
Now, the game has the player make one final decision: who will activate the purifier. The radiation levels are fatal once the purifier is activated, so whoever goes in isn't coming out (RadAway. Rad-X and Radiation Resistance do not matter, as it is a cut-scene).
The obvious choice is that either the player or Sarah Lyons must sacrifice their life to get the purifier going and prevent the destruction of Project Purity. If the player hasn't figured it out from James ' notes and recordings, the purifier password is 2-1-6 (referring to the verse from Revelation which Catherine loved). If the player follows James to the purifier when he first enters the Memorial in The Waters of Life. James points out the code and repeats the passage. The player is supposed to infer it from James' dialogue about the Lone Wanderer's mother, and the picture hiding his safe in the Vault 101 clinic. If the player chooses to convince Sarah to do the job, the
Lone Wanderer will tell her the code in dialog. If the player has the Broken Steel add-on, the player's Karma will be raised by 1000 if he/she decides to activate the purifier themselves. No Karma is gained if the player sends in Sentinel Lyons or one of their companions.
Without Broken Steel . if the player character chooses to sacrifice themselves, once entering the password they slump away from the purifier password panel. A statue of Thomas Jefferson is revealed inside the central chamber as it is purged. A series of still images recounting the player's actions throughout the game is shown. The relevant section of ending video ends with Sentinel Lyons looking at a shining pile of goo at the control chamber's bottom - which is, presumably, all that is left of the player.
If you choose to activate the purifier yourself, this is the time to insert the modified FEV created by President Eden into the water filter, assuming you want to and didn't give it to Elder Lyons. As in Fallout 2. the only creatures spared by the modified FEV are pure strain humans who are still within vaults and the Enclave. This would reverse a great deal of genetic damage done by the nuclear apocalypse, but at the cost of complete eradication of nearly all life on the wasteland. This decision is actually listed in the player's Pip-Boy 3000 as a separate quest called Project Impurity ; however, it cannot be completed if the player turned in the Modified FEV to Owyn Lyons before departing the Citadel.
Inserting the modified FEV lowers Karma by 1000 and has a long-term game impact if you have downloaded Broken Steel. The Aqua Pura thus created by purifying the water is now infected by the virus, and as your character is not a pure-strain human as Eden believed, it will cause a negative effect on your SPECIAL stats and kill you if four or more are consumed in quick succession. A warning will come up that reads Continued consumption of FEV-laced water will be fatal to remind you of this fact.
Without Broken Steel installed, your companions will refuse to do the job. Naturally, of the seven, four would die just as easily as you, and they aren't willing to do it. Even Fawkes, Sergeant RL-3, and Charon who are highly resistant or outright immune to radiation, will simply decline. With Broken Steel. however, the latter three will now agree to do the job, as they can do it safely.
Fawkes. one of the companions the player may take with them, has great radiation resistance (or possibly immunity) as a result of being a super-mutant. However, like any other companion character, his dialog option has him refuse to enter the chamber, mysteriously claiming it is the player character's "destiny."
I'm sorry, my companion, but no. We all have our own destinies, and yours culminates here. I would not rob you of that.
Whether this is because Fawkes believed himself unable to survive, or if he had other reasons for declining the player (such as feeling that the debt had been repaid, or having a genuine belief in destiny) is not explained. Regardless, Fawkes turns out to be a red herring: the player is forced into a decision to either sacrifice themselves or make a true hero (Sentinel Lyons) make the sacrifice for them. Fawkes may nonetheless follow the player into the chamber if his following distance is set to "close".
If the Broken Steel add-on is installed before beginning Take it Back!. Fawkes will agree to enter the chamber, stating this.
"Ah, of course! My immunity to radiation makes me a far better candidate for surviving in there."
Fawkes will be briefly staggered when the purifier activates, but does not collapse like the player or Sarah Lyons would. He will instead walk around the chamber and kick the purifier panel as the screen fades to white. The end will show him as "A True Hero" instead of Lyons.
As intelligent as the canine may be, there is no option to have Dogmeat activate Project Purity. Instead, a new dialog option opens up, wherein the Lone Wanderer can say some final words to his or her canine companion, stating: "I think it's time for us to say goodbye, old buddy. Take care of yourself, okay?" Dogmeat whines in response.
Even if you took Sergeant RL-3 (a Mister Gutsy combat robot, which is immune to radiation) into the rotunda with you and command it to go in to turn on the purifier he declines and says:
Soldier, you ought to be ashamed of yourself. This is your fight! You gotta finish what your daddy started! Stand strong and get your ass in there!
There is no Robotics Expert dialogue option in the conversation.
Like Fawkes and Charon, if Broken Steel is installed before starting Take it Back!. RL-3 can be ordered to go into the control chamber and activate the purifier. He will state that his "superior design and programming" will be able to withstand the hostile environment, followed by an exclamation that "This will mean a battlefield commendation for sure." After starting the purifier, he apparently cringes from the radiation spike, but is otherwise unharmed. The ending will show him as "A True Hero" instead of Lyons.
Charon will not activate the purifier for you. The dialog is as follows:
Come on, we both know I've saved your ass enough times already. This one's on you.
Just like Fawkes, if Broken Steel has been installed before this quest, Charon can be told to enter the control chamber and turn it on. The player will remind Charon that he must obey whoever holds his contract, then order him to enter the control chamber, to which Charon grudgingly agrees. Unlike with Fawkes or RL-3, no mention is made of the fact that Charon, being a ghoul, should be unaffected by the radiation in the chamber. If Charon is used to start the purifier, he will replace Sarah Lyons as "A True Hero" in the ending movie.
Butch. understandably, will refuse out of fear of dying and of becoming a ghoul, stating:
That chamber? Right there? With all the radiation? Man, no way. I'll end up dead. Or worse. I could be one of them ghouls! Ain't gonna happen.