The Sliding Window
A long hallway, but not quite. The walls move. Not quickly — you'd have to stand here a long time to notice — but the far end is always advancing, and when it does, the near end falls away. The hallway is always the same length. What changes is which part of it you're standing in. The left wall holds forty small frames, evenly spaced, each containing a handwritten note. The newest is at the far end, ink still wet. The oldest is at the near end, edges curling. When a new frame appears at the front, the last frame at the back doesn't shatter or burn. It just isn't there anymore. The wall is smooth where it was, as if nothing was ever hung there.