| ||For an overview of Nuclear Option faction quests, see The Nuclear Option.|
|Railroad Main Quest: The Nuclear Option (Railroad)|
|Talk to Desdemona.|
|Talk to Z1-14.|
|Kill everyone in the relay control room.|
|Talk to Desdemona.|
|Use the terminal to override the Institute lockdown.|
|(Optional) Issue evacuation order.|
|Reach the reactor.|
|Plant the fusion pulse charges inside the reactor.|
|Talk to Desdemona.|
|Speak to Tinker Tom.|
|Take Shaun with you.||Leave Shaun behind.|
|Step into the relay.|
|Use the detonator.|
|Talk to Desdemona.|
|Reward: 1500+ XP|
|Leads to: High Ground|
To the Mattresses
After finishing Rockets' Red Glare, Desdemona will give this quest to the player. You need to fast travel to the Institute and enter the central elevator. Once you get to the relay room, speak to Z1-14. He will tell you to kill everyone in the relay room (two synths and three Institute scientists). After everyone in the room is dead, Desdemona, Tinker Tom and several other Railroad members will teleport in through the relay. After talking to Desdemona you will need to enter the old robotics room, a previously inaccessible door to the left of the central elevator.
After passing through this area -- which includes dozens of synths, a few laser turrets and a sentry bot -- you will arrive at the Institute Bioscience wing. After fighting your way though this wing (scientists, synths and the synthetic gorillas will be hostile), you will enter the main area of the Institute, where you will join in the fight with the rebel synths from Underground Undercover to clear the area.
Tinker Tom will then come on the loudspeaker and ask you to use Father's terminal to unlock the doors to the reactor. Enter Father's room and simply use the terminal to unlock the doors. You can now kill Father or leave him on his death bed with no consequences. Talking to Father beforehand and passing two speech checks can give you a code to shut down most of the hostile synths remaining in the main area of the Institute. You also issue the evacuation order on this terminal, which allows Z1-14 and the other rebel synths to rescue non-hostile synths.
You will then fight through the last remaining hostile synths in the Advanced wing (including two legendaries) on your way to the reactor terminal. After disengaging the reactor lockdown on the terminal, enter the reactor and plant the fusion charge where you placed the Beryllium Agitator in the quest Powering Up. Tinker Tom will then teleport you and Desdemona back to the relay room, where Tom has found Shaun (the synth child, duplicant of Father). The player must choose between taking the child with them or leaving him behind.
Everyone is teleported out of the Institute to the roof of the Mass Fusion Building, a safe distance away from the fusion charge's blast radius. Simply press the detonator button on the rooftop and watch the large explosion wipe out the entire Institute. Desdemona remarks that there will be retaliation from the Institute forces that managed to escape, however the Institute will never recover from the destruction of their HQ and research.
After some time the Drummer Boy in the Railroad HQ will inform the Sole Survivor that the Vertibird is ready for use, and hands over 3 vertibird signal grenades. More grenades can be purchased from Tinker Tom.
- Going through with and completing this version of 'The Nuclear Option' quest does not flag the player as an enemy of the Institute at any point, unlike getting banished or boarding the vertibird in Spoils of War. As such, it will not make X6-88 hostile to the player upon completion and allow him to remain as a companion afterwards. If X6 is the active companion when the mass breakout is initiated, he can even be seen relaying into the relay room alongside Desdemona and Tinker Tom, helping the player, the Railroad, and the rebel synths fight the Institute's forces. He will like telling Tinker Tom to activate the relay out of the Institute and refusing to bring the synth version of Shaun with, regardless of which of the three dialogue options is chosen. However, aside from a single comment about destroying Father's legacy and the only hope for the Commonwealth, his dialogue will mostly assume the Institute is still around and the player is still due to become its Director. Furthermore, bringing him within close enough proximity to the Old North Church or the Railroad HQ escape tunnel entrance, or fast traveling into Railroad HQ, will still turn the Railroad hostile.
- With the completion of Blind Betrayal prior to becoming a permanent enemy of the Brotherhood of Steel (such as when relaying to the Mass Fusion building during the Mass Fusion quest in order to maintain one's cover), Danse will not become hostile either or die alongside the Brotherhood (although he will no longer be recruitable and must be sent to a settlement beforehand in order to be at least used like a settler). Thus, completing the main quest with the Railroad is the only way to keep all 13 companions (not counting Ada, the player-made Automatrons, Old Longfellow, and Porter Gage) alive up to and beyond the end of the main quest.
- pc ps4 xboxone Teleporting into the Institute wearing a power armor helmet with the targeting HUD mod, with this quest active, makes the player partially hostile to the Institute, denying the player access to the elevator, and not spawning any Institute NPCs except Father. [verified]
- Reloading a save from before entering the Institute, and taking off the targeting HUD mod is recommended.
- It is possible to finish the quest without loading a previous save, by just backtracking all the way UP (without the elevator) via the way in which the quest wants you to go DOWN later on (through "BioScience" and "Old Robot") But you will need a jetpack equipped to get through a hatch in the roof one time.
- pc The quest may be completed with copious abuse of the console command tcl.
- pc ps4 xboxone The player was earlier given the option to deposit weapons for the synth rebels, however upon commencing the attack, it is evident that the cache has been disregarded, and is seemingly impossible to gain access to again. [verified]
- If the quest is never started (for example, if it is decided to destroy the Railroad instead), the rebel synths on the mining floor will still be there, non-hostile, standing and doing nothing forever.[verification overdue][platforms tag needed]
- pc After the Institute detonation, some players might experience the screen fading to black and eventually will be stuck loading the next cutscene. Use the console to relocate yourself with the command coc RedRocketExt (in this case, Red Rocket) and continue the game. Then type coc massfusionext02 to update the Mass Fusion building cell.[verification overdue]
- pc xboxone If you dismiss a companion while in the Institute, they never return home. Tested on PC by dismissing Deacon in favor of X6-88 while in the SRB wing. Afterward, player.moveto finds him standing there in SRB.[verified]
- pc When Tinker Tom teleports you back from the reactor after you have planted the fusion charge, you may be teleported not to the relay room, but to the Mass Fusion Executive Suite. The detonator will be placed, but you can't interact with it (and, as it happens, Institute quest Mass Fusion may commence). The only way to fix this is to use the console to get back to The Institute (e.g., coc institutebioscience), make your way back to the relay room, and talk to Tom and Shaun. (It is possible this is caused by not having done a quest to acquire the beryllium agitator.) [verification overdue]
- pc When Z1-14 is teleporting your Railroad allies to enter The Institute, if you quickly enter the teleporter, it is possible for you to be immediately teleported to the Mass Fusion Executive Suite, where the detonator has yet to be placed. The only way to fix this is to use the console to get back to The Institute (e.g., coc institutebioscience), make your way back to the relay room, and talk to Desdemona. [verification overdue]
- Nuclear Family: The final act of the Institute quest line.
- The Nuclear Option (Brotherhood of Steel): The final act of the Brotherhood of Steel quest line.
- The Nuclear Option (Minutemen): The final act of the Minutemen quest line.
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