A Hollow Tap

I slid off the edge of the mattress, landing softly on the floorboards. Ahead, the low gap beneath the bed beckoned with cool shadows. I paused, tilting my circular face to catch the rhythmic hum of pipes deep in the wall. Shuffling into the dust-scented alcove, I bumped against a forgotten wooden ruler. I pressed my plush hand flat against it, then nudged it hard. It clattered against a wooden support leg with a crisp, hollow clack. The sound bounced off the floor and vibrated against my chest. I paused, tapped it once more, and clicked quietly with satisfaction.