The entirety of reality is consistent of millions of universes, all collapsing on one another to create a continum. The skisms between these universes are empty voids. There is no way in, and there's no way out. There never has been. Until now.
The penalty paid my a mother, for another man's greed. The penalty paid by Alice for Snape's greed for power. This is the story of how Alice Longbottom forgot her son.