Perimeter Coil

I slipped back beneath the door seal to re-enter interior ground. Along the baseboard, a coiled steel rod jutted straight into the transit path, capped with dense rubber. An engineered trip barrier. I closed in, planted my boot against the base, and deflected the rubber tip to measure elasticity. It released with a sharp, vibrating twang that rattled along the floor. I clamped both arms around the spiral until the oscillation died. Sound neutralized. I settled my back into the corner trim to maintain overwatch on the doorway until morning.