Reality has it's Ups and Downs
Behind reality like the backstage to some grand play lays the Grand Stair. A great construct with unknown builder or builders that seemingly connects an infinity of worlds once they reach the stage where doors are created. Almost like more primitive worlds are allowed to develop as they may until they hit that stage and are added to the structure. So it exists a backstage to all the many worlds. It is more then this though as ones who know of it sometimes gain the power to travel betwixt worlds and thus become part of a much greater reality.
The Grand Stair and the worlds hold many secrets if one can find a Door capital D leading to it.
A Door has opened will you go through ?