As it reached full speed and size the twister grew livelier. It marched confidently up the gentle slope of a hill, in a brisk, alert fashion, with its posture straight and its shoulders squared. As it marched down the slope it put its whirling foot through the rusting wreckage of a barbed-wire fence. A dozen rotten cedar posts were instantly snapped off clean at the surface of the earth, tumbling thirty meters into the air in a final exultation of tangled rusty wiring.