This story takes place in a universe entirely different from our own. Instead of a whole lot of empty space, there's a whole lot of empty room. I mean, empty rooms. Like bedrooms and the sort. It consists entirely of what we would consider to be Indoors.
Instead of mountains and valleys, there are spiral staircases and auditoriums. Instead of gullies and trails, there are passageways and corridors. Instead of caves and canopies, there are chambers and balconies. And there is no outer space, for this mansion extends to infinity.
Now, when we think of buildings, we know there's wiring and plumbing within the walls and floor, things that must lead outside. And seeing as how this entire universe is inside, these pipes and wires lead out of the universe itself. In this way, a toilet is a function of this world, a law of physics if you will. When you flush, the contents vanish. There is no need to explain where the contents go; it is simply one of the underlying foundations of logic. A law that you cannot break. Therefore, all toilets are indestructible...as are the walls, floors, ceilings, and doors.
Yes. Doors. Doors are rather important. We consider this entire world to be Indoors. Here, there's no real meaning of the word in, but doors are certainly an important issue. Doors are what allow one to control the universe. Doors are powerful. But more precisely, keys are powerful. Every boundary between one room and the next has a door. And every door has only one key.
There are plenty of communities where the leader has a ring of keys on their belt and all doors are kept open. But on the boundaries of these communities, the doors are kept locked, either by the leader himself, or by some unknown civilization on the other side. Most doors are a mystery. Some doors are not even known to exist. You see, a door can come in many shapes and sizes. Some are ten meters tall and made of solid brass; others are in the form of loose floor boards.
And keys are also mysterious. Many children have necklaces that dangle a solitary key. A key whose door has been forgotten. Keys are passed down from father to son, mother to daughter. They hope that one day the key will find its door. Every key is sacred.
Currently, one very precious key is hanging from a little boy's neck. He has no idea what power the key possesses. He has no idea what door it opens. One day, when he somehow finds his way out into the world, he will find that door. But for now, he is only eight years old and playing a game of jacks on the hardwood floor in the hall. And one more thing, his name is Sam.
Now the story can begin.