Nuclear Family

Nuclear Family is the final Institute main quest and an achievement/trophy in Fallout 4.

Detailed walkthrough
Return to the Institute to speak with Father and listen to his final words before he dies of end stage cancer. Shown next is the ending scene, showing glimpses of the Sole Survivor's life prior to the Great War and their experiences since.

This short quest completes the Institute questline. The player character may continue their adventures in the Commonwealth afterward.