I found myself face to face with a long line of people resembling extras off the set of Night of the Living Dead: shuffling along, pale and twitching, empty cups in hand -- murderous. Miserable. No matter that the air was rich with vapors of fresh-ground beans and warm muffins; no matter that the soft piped-in Vivaldi poured over us like steamed milk. These angry zombies were rushing to work, and their eyes flashed fair warning: Don't mess with us. We haven't had our coffee.