Waterhouse reaches out and catches a yellow-brown elm leaf that happens to fall through the air before him. He hunkers down, plants his cigarette in his mouth, and, using both hands for steadiness, draws the sawtooth rim of the elm leaf across one of the web’s radial strands, which, he knows, will not have any sticky stuff on it. Like a fiddle bow on a string, the leaf sets up a fairly regular vibration in the web. The spider spins to face it, rotating instantly, like a character in a badly spliced movie. Waterhouse is so startled by the speed of the move that he starts back just a bit, then he draws the leaf across the web again. The spider tenses, feeling the vibrations.