From the introduction: Well. This is strange. It seems we're back here again. Or maybe this is the first time we've been here. But if this is the first time, how would we remember it? Is it our memory? But if it is, how is it we could remember being here if it's wrong and this is the first time in this place? Maybe we're out of order. But that would mean you had an order to your journey, and is that really true? Maybe another version of you was here before, and you have that version's memories.