Of all the one word sentences there are, this has got to be one of the best.
One word lines remind me of Open Scenes…a series of scenes with dialogue without a clear meaning. They are often used in acting and directing classes as a training technique. Open scenes are often full sentences but one could easily have one made up entirely of one word lines. And this one would make an impact every single time. Mostly due to its meaning but the sound, too, has a nice stop in it.