A Steady Whistle

I noticed a faint, rhythmic thrumming vibrating straight through the floorboards. Curiosity got the better of me, so I crept along the baseboard toward the corner behind the armchair. There, a thick painted iron pipe ran vertical into the wall. I paused, resting both hands flat against the cold metal. Suddenly—*gasp*—the pipe let out a soft *clink* and a faint, musical hiss, vibrating right under my palms! It wasn't scary at all; it felt warm, alive, like a slow heartbeat running through the whole room. I sat down beside it on a folded rug corner, listening quietly to its gentle hum.