Update: I was unfortunately not aware of Shamus Young's severe criticism of Fallout 3 available here to link in the original piece and I regret that. It dovetails rather nicely with what I've written and it's much better executed than my piece. I strongly recommend anyone...
It all began months ago: first a vague sense of uneasiness, then blackouts that would last for several minutes. Now, you are experiencing vivid hallucinations several times a day. They went from being short fragments, akin to fleeting dreams with no meaning whatsoever, to complete episodes with strange apparitions acting in front of you, having conversations and even in certain cases addressing you. A story is unfolding right there before your eyes, blending in with your daily life, growing in complexity and threatening your sanity. Again.
The only possible explanation makes you feel nauseous. It has been years since you left the Hanwell Mental Institute, finally cured, and you would not have returned to it for anything in the world. It was a despicable place filled with hatred and pain; the inmates often more human than the doctors in charge. But there is no denying it, you are recognizing the faces in your visions, the stories are becoming too familiar and they are unbearable. Something terrible happened here and it has somehow affected you. It was dormant in your memories for years until today. You can no longer discern reality from the imaginary, and you will not be able to live in peace until you unravel the past and find out what happened to you. It is time to come back and face the horrors awaiting in the asylum.
Decay surrounds you, dread around every corner. You feel imprisoned while traversing the endless hallways, yet you must keep striving to reach the truth. With every step you take, a dark menacing presence draws nearer. Unimaginable atrocities occurred between these walls... What have they done in here? What have they done to you?