This movie is about aliens who control humans minds and reality.  Everyone is located on a spaceship that simulates the reality of earth in the 1900’s to around the 1940’s or so.  It is about a detective who is living through this movie and strange things happen everyday in this reality and then when they go to sleep and wake up, it’s all been erased and there is a new day, but the detective starts to put things together, and eventually there is a super cool scene near the end of the movie where he opens up a door to “outer space” and almost falls out of the ship into outer space but closes up the door and goes back inside the ship they are in.  The aliens are studying the humans on this pretend earth ship, so that they can learn why they do the things that they do, it seems like the aliens don’t have the special spark that makes humans so special and are trying to figure it all out so they can apply what they learn to their own species to develop their own species.  None of the humans know what’s going on at all, ever !