The Dreamworld

The story starts with the main character, a struggling writer.  He has a very creative imagination, and all his life, he has dreamed of inhuman intelligences, of worlds beyond our own.  He writes, but his stories are just a bit too strange for humanity.  (Alternatively: Start within one of his stories.)

Eventually something happens and he wakes up in the world he was writing about... or, it appears, some sort of mishmash of elements from all his stories.  He is told that he has pierced into the dreaming, into the world of his imagination.  He asks more, learns assorted stuff.  The dream intelligences tell him that there are others who have contact with the dreaming, and give him hints on how to find one of those others.

Back in the real world, he is able to find this person.  She  is amazed that he knows so much about her dreams, even ones she never put to paper.  Also a little worried.  He tells her (as instructed) that soon she will no longer be just be dreaming of this world, but enter the dream-world herself.

The next night, he wakes in the dream, and is directed to meet the other dreamer.  They talk, and then agree to talk in the real world.

In the real world, after a bit of uncertainty, the other person shows up on the place they had agreed upon in their dreams.  He is delighted of the proof about the dreaming, but she is leery of the dream-intelligences.  If they are real, what do they want?  Humans were never in the dreams, what could their intentions be?

The next night he dreams again, and the dream-intelligences ask him to stay a while.  They have built a human-style abode in the dream-land, and ask him to spend the night there.  He is amused by the prospect of dreaming within the dream, but sleep anyway, and sleeps normally - in fact, for the first time in his life, he lacks any strange dreams, but rather he dreams of the other dreamer in a conventional dream-dream.

Later the dreamers hurriedly return him to the real world, and he is amazed to find that almost an entire day has gone by in the real world - the time spent in the dream-land corresponded to the real world dream.

The other dreamer is knocking on his door, and she tells him that things have been happening.  Strange happen-stances, things herding her in a direction to meet him.  She is suspicious, unstable seeming.  She worries that she might be going insane, or that the real world is controlled by the dreamers.  She demands aloud to be brought into the dream-world.  A sheet of paper blows in the window with a single world on it: "Sleep"

They both go to sleep, at her insistance, and he awakens in the dream world.  He is able to find her.  Once together, she asks the dream-intelligences what is going on.  They say that both worlds are real, and, yes, they have limited control of what happens in the normal world - just as the dreamers can exist and have an impact in the dream world, they can interact with the real world.

The other dreamer denies this - the dreamers awaken into the dream-world, but the dream intelligences don't awaken into the dream-world.  She posits that the normal world is actually a simulation, and that this is the actual real world.

The dream intelligences verify that, no, the normal world is a simulation, but it is a real simulation - experiences that matter occur, and are no less false than any other.  Instead, they note that this world is simple one they have less control of.

The other dreamer inquires further - if this is the physical world, and the other world is one of only experiences (a distinction constantly naysayed by the dream-intelligences), what about the other people from their lives?  Do they all have real bodies here in the physical world?

No, there are only very few real humans.  The simulation they had was based on historical research, and populated by simulated humans.  The two of them shared a reality, but while other humans exist, they are in different simulations.

They asked what happened since the history where humans lived?  Well, they are informed, the humans have died out.  The intelligences, having been created elsewhere by their own deceased forebearers, were able to observe the humans from a distance, but by the time they arrived on the humans' world, all the humans had died.

So they recovered genetic material of humanity, and grew humans and raised them in the simulation.  But the first batch had extreme trouble when they were brought into the physical world.  The second batch were given dreams of the physical world, so it would be more familiar.

But now the two had discovered the reality before the intelligences expected it.  The plan was to bring all of the second batch of humans into the physical world, and then have them raise further human children in the physical world directly - a sort of bridging.  All this for the human race to exist once more.  To bring back a race that had once destroyed itself.