| ||For an overview of Nuclear Option faction quests, see The Nuclear Option.|
|Brotherhood of Steel main quest: The Nuclear Option|
|Speak with Elder Maxson.|
|Go to Father's quarters.|
|(Optional) Speak to Father.|
|(Optional) Issue evacuation order.|
|(Optional) Activate synth deactivation code.|
|Use terminal to override Institute lockdown.|
|Reach the reactor.|
|Plant fusion pulse charge inside reactor.|
|Talk to Elder Maxson.|
|Get to the Relay.|
|Talk to Proctor Ingram.|
|Take Shaun with you.||Leave Shaun behind.|
|Step into the Relay.|
|Activate the detonator.|
|Talk to Elder Maxson.|
|Reward: 1500+ XP|
|Leads to: A New Dawn|
After dropping into the hole made by Liberty Prime (completing Ad Victoriam), the Brotherhood insertion team will find itself around the corner from the teleportation room where the Sole Survivor first entered the Institute. Elder Maxson will hand out an explosive charge to place on the Institute reactor. Proctor Ingram stays behind to get the teleporter working, and the rest of the team proceeds forward.
The Sole Survivor must go through the old Robotics wing, now a ruined section of the Institute, eventually coming out in Bioscience. If the Sole Survivor has not retrieved the experimental serum for Virgil yet, they should do so now as it will be their last chance.
Once in the main section of the Institute, they must clear it of enemies. Once done, they must go to speak to Father. Father can be persuaded with a Speech check to reveal the password to disable a part of the synths that protect the Institute. Once finished, they can do as they wish with Father, and issue the evacuation order if they wish to. Afterwards, they must enter Advanced Systems, then clear the section of enemies, and get to the reactor. After doing so, they must activate the terminal, activate the radiation sweep, and then disable the reactor's shielding. Then, they must plant the explosive. They will then be teleported out of the reactor section. Ingram will explain that Shaun, the synth child, showed up. The Sole Survivor must decide what to do with Shaun, and must then step into the molecular relay.
Afterwards, Maxson will tell them that the honor should be theirs to activate the explosive. After doing so, Maxson will tell them to return to the Prydwen and the quest will be completed.
- If Paladin Brandis was convinced to rejoin the Brotherhood ranks after the Lost Patrol, he will be part of the forces entering the Institute. Be warned, he can die during this mission.
- With 10 Intelligence and Idiot Savant rank 2 triggering, this quest can yield a staggering 9750 XP upon completion.
- After this quest has been completed several synth soldiers (along with a suit of power armor) will occasionally appear floating above the now cratered remains of the C.I.T. ruins. They are not hostile unless shot and even then don't pose much of a threat since they are swimming. The power armor is unfortunately stuck floating forever.
- The armor can be retrieved, without the use of console commands, by exploiting the physics glitch related to engine blocks. Though difficult, one can position themselves over the armor, let go of the block, and get in, thus depositing the player and power armor in the water below. Due to the rarity of engine block models in the world, and the considerable distance they must be carried to the Institute crater, this method is a considerable undertaking.
- Shortly after the explosion, the ending cutscene will start.
- PC After blowing up the Institute one may find themselves unable to talk to Elder Maxson to continue the quest, or he may be absent. For the PC, open the console and use commands prid 1cc18, recycleactor and then moveto player to teleport Elder Maxson to the player's location. [verified]
- One may not need to use recycleactor, just prid & moveto.
- PC Playstation 4 Entering and exiting the FEV lab may cause several synths to become allied to the Brotherhood and attack other synths. [verified]
- PC Quest may become stuck on "Speak with Shaun" with no way to move forward without using the console. [verified]
- SetStage MQ302BOS 720 (taking Shaun) or SetStage MQ302BOS 730 (leaving Shaun) will fix this issue.
- Nuclear Family: The final act of the Institute quest line.
- The Nuclear Option (Minutemen): The final act of the Minutemen quest line.
- The Nuclear Option (Railroad): The final act of the Railroad quest line.