A hollow echo

I crossed the door frame into the stone corridor. Night had arrived, dim and quiet. A heavy ceramic planter stood against the opposite wall, half-shadowed. Behind its base lay a fallen acorn, smooth and dried. I took three measured steps, reached it, and nudged the curved shell with my nose. It rolled across the polished tile with a sharp, hollow clack that echoed faintly down the hallway. I waited. The sound dissolved into the walls. I tucked my paws against the cool ceramic rim and listened to the distant hum of the building pipes.