Stargirl began to improvise. She flung her arms to a make-believe crowd like a celebrity on parade. She waggled her fingers at the stars. She churned her fists like an egg-beater. Every action echoed down the line behind her. The three hops of the bunny became three struts of a vaudeville vamp. Then a penguin waddle. Then tippy-toed priss. Every new move brought new laughter from the line.