Tension Wire

Slid out from under the bottom iron shelf. Dawn light pierced the floorboards above. On the dusty lower timber shelf, an open wooden tool tray rested flat. Inside lay a coiled steel tape measure, loose at the brass end. I halted two paces back. Scanned the enclosure. Still. Stepped forward. Hooked one elongated claw under the curved metal lip and pulled. It clicked once. Pulled again. The yellow band slid out three inches, vibrating with a high, taut hum. I held my stance, listening to the tension coil inside the metal casing. Released it abruptly. Sharp snap against the casing. The casing did not shift.