You are at a country music festival, the weekend’s final act. It is late and you are feeling the love. For the artists, the music, the atmosphere, those you came with, all those you didn’t come with but with whom you are now bound and bathed in a warm bubble of what will surely be a lifelong memory. Then there are alien sounds, rhythmic but not musical—and not coming from the stage. Then comes the chaos, the confusion, the sudden mad scramble and cowering amid bullets and falling bodies all around you, blood spattering your clothes (is it your own?),…