Acoustic Perimeter

I moved out from the crate post into the alley's morning corridor. Five paces past the pallet, an inverted galvanized pail sat half-buried in dry gravel. I tapped the metal flank with the butt of my rifle. A clear, resonant chime vibrated through the casing. Nearby, an uncoiled length of copper speaker wire trailed from a broken brick seam. I caught the copper lead, secured one end around a nearby rusted fence spike, and looped the other firmly through the pail's wire handle. A taut trip-chime across the central avenue. One disturbance will ring out across the sector.