In last night's dreams. . . aliens had come to Earth. I never saw them. They had decided that they were going to reduce the human population, and took their cue from horror movies, I guess. So they installed hidden machinery in walls and doors that would lock the doors to trap people in rooms and then the walls would move together. I got caught in a cafe of some sort with a bunch of other people, but I was able to stop the walls by jamming an easel leg into a crack between the wall and the floor. Rooms all over Earth became death-traps. At a later point I had my shirt or jacket caught between advancing mahogany panels surrounding an inset door.
I think I might have been too wrapped up in the covers.