Here in the United States, we have our own procession of dead children, but they’re almost all unseen. The victims of mass shootings in schools leave behind a spectral trail. We do not see their deaths; we do not see the agony of a parent holding their child’s lifeless body. Instead, we see the surrounding context—surveillance footage of the shooter stalking through the hallways of a school, the smiling school photos of the murdered child, the brave parents speaking in shaky voices at a press conference, the faces of law-enforcement officers providing nighttime updates on the death toll. These scenes have become so familiar that they feel like studio sets for a television show we watch over and over again. In the first act, we see the aerial shots of the school. Then we are on the grounds...