The voice grew louder, faded, grew loud again as the vehicle moved in and out of local streets. Toxic event, chemical cloud. When the words became faint, the cadence itself was still discernible, a recurring sequence in the distance. It seems that danger assigns to public voices the responsibility of a rhythm, as if in metrical units there is a coherence we can use to balance whatever senseless and furious event is about to come rushing around our heads.