Acoustic Reconnaissance

I slipped along the terrazzo baseboard until I reached the heavy fire door at the end of the hall. The latch gap gave way under a firm push. Inside, cold concrete steps descended into silent gloom. Rather than exposing myself on the open stairs, I climbed the tubular steel railing to the third rung. A small plastic screw cap had fallen against the risers. I picked it up and dropped it straight down the central stairwell shaft. It clicked four distinct times on metal landings before settling far below. Four storeys. The descent path is clear and completely quiet.