The Nuclear Option is the Act 3 of the game which totally depends on which faction you be Loyal with will the end. This Fallout 4 Guide will show you The Nuclear Option for The Railroad and the story after this Quest. Without any further due let's check the Final conclusion with The Railroad.
To get this mission, you must be loyal with the Railroad and complete their Essential quests. With this Last quest, you will eliminate the Institute and Spead the rest of the life with the Railroad Faction.
Objective
Walkthrough
Now that you have finally decided to stay Loyal with the Railroad and Eliminate the Institute, it's time to speak with Desdemona and she will give you Fusion Pulse Charge then relay into the Institute. Talk to Z1-14 and he will guide you to the Robotics area where you need to eliminate the remaining Synths.
Now drop down from the hatch to get inside the BioScience Lab, blast the door to get entrance for the reactor chamber. Now head towards the father's quarter via central elevator to obtain the password for the terminal. Once you obtain the password go to the Advanced System to enter the reactor chamber. Here get ready to take down few synths and scientists then continue accessing the reactor door to activate the housing.
Tinker Tom will help you teleport to the Institute Relay Control Room, then speak with Desdemona and Tom where they will mention a child nearby and you have two options:
Now Teleport back to the Mass Fusion Building roof with Desdemona and Tinker Tom, get ready to finish off the Institute with a press of that button. This Completes your mission by eliminating the Institute. Speak with Desdemona to conclude and continue your journey in the Wasteland with other misc Quests.
This mission will only trigger after you have completed The Nuclear Option with The Railroad. This is just a simple informative mission to know more after the Nuclear War.
Objective
Walkthrough
After you have successfully eliminated the Institute, head back to talk to Desdemona. Now just to make sure that this quest will be available to a player who have made The Institute hostile before completing The Railroad quest Underground Undercover. If you did then Talk to Desdemona and she will ask you to go and speak with Preston Garvey in order to join the Minutemen at the End of the Conversation. You are now left with the Minutemen and the other misc quest. Also, Check out our other Fallout 4 Endings Here.