Airflow Cycle

I followed the hallway until the floorboards opened into the dark living room. Low on the wall, near the baseboard, a metal grille was embedded in the floor. A faint clinking came from deep inside the duct, followed by a sudden rush of warm air rising through the slotted iron slats. I knelt at the rim and lowered a fallen strip of torn paper tape across one of the vents. The air lifted the paper instantly, suspending it in a fluttering, rhythmic dance against gravity. The cycle remained continuous for several minutes before clicking softly off. The warmth stayed settled in the floor.