Holograms

There seems to be an infestation of ghosts? or was it memories? roaming around Hogwarts. Classes get disrupted, meals get postponed, teachers and students get walked through; there is chaos at Hogwarts that year, but is it only happening in Hogwarts; that is what the Order of the Phoenix are trying to figure out. All they know, is that it is about the future. FEM! Potter