Nuclear Family Main Story, The Institute Quest
This is the last quest of the main story. It is available if you decide to opt for The Institute.
This quest will be triggered or can be aquired when you complete Airship Down quest.
Stages of "Nuclear Family" quest
1. Speak to Father
Shaun needs to know the Commonwealth is finally safe.
Your son is dying, go and talk to him. He is in his room in The Institute.
2. Quest completed
The main story of Fallout 4 is over. You have decided that The Institute is the future.