fter seeing “World War Z,” I walked through Times Square, and, as I made my way to the subway, I wondered why the movie—which is, after all, just a very expensive zombie flick—had excited and disturbed me so much. On Broadway, there were no zombies in immediate sight, only a happy and friendly crowd. Yet I felt a vague uneasiness at the sheer number of people milling about—a sense that they could all be transformed into something malevolent or frightened. Absurd? Mere paranoia? Maybe, but who hasn’t felt a tinge of paranoia while walking on crowded streets, particularly streets thronged with barkers for standup comics? The movie, which was directed by Marc Forster and was written by Matthew Michael Carnahan and a host of collaborators, evokes the hectic density of modern life; it stirs fears of plague and anarchy, and the feeling that everything is constantly accelerating. At times, it has the tone and the tempo of panic.