You saw visions in the darkness and heard whispers from nowhere. In the short time that you had to peer through the door and see what happened to your sister when she touched it, you think that you've understood something about that place. You will receive some information about a-place.

The place is where you go to when everything resets. When you are in the place, you have seen shadows and silhouettes that crumbles into dust as they pass through the silent, shifting ashen curtains.

You force yourself to think back of your sister's death (“not just death, murder”, a small part of your mind whispers. You didn't mean it, you didn't mean any of it, but you still caused it, the way mages do, right?), when she fell and touched the door, what you saw right before the door slammed shut and she fell limp (dead). For the briefest moment you saw her, there, across the door. But gone before you could really see anything more except her shadow, her afterimage, which lingers until the door closes completely.

You made a door to the place and it killed the one who touched it. The moment she touched it she went there - as the spell intended, but she didn't stay, not quite. A shade of her remained when she herself was gone…

You pull together all your magical understanding and the strange things you recall from your tome. Eventually you formulate a theory.

The place is where people's souls (whatever they are, whatever it was that appeared in the place with your sister's appearance when your sister's body was lying on your floor) go upon death, but not exactly the afterlife (whatever afterlife means), which is presumably where your sister's soul actually disappeared to. It's a place where people pass through, leaving behind some kind of shadow or after image, the things you and the other loopers see when you are in the place. You're not sure what those shadows really are, only that they are casted by the dead.

The fact that you and the other loopers go there every reset is very strange, considering that most of you do not recall dying. Maybe it also has something to do with souls. Maybe something happens to your souls when you loop that causes you to temporarily go to the place.