There was a single, sharp tap of the drums followed by a rapid succession of beats as the crushed velvet curtains spread and the audience gasped: for Tran had taken her position in the box and was even now being secured as Williams struck a gunfighter pose and his hand hovered next to his weapon. “Ladies and gentlemen, I think it goes without saying,” said the announcer over the speaker system, “Do not try this at home.” Williams relaxed his entire body even as his mind cycled through the calculations—altitude, the breeze, humidity, temperature, the curvature of the earth, the spinning of the earth ... It was, like music, a largely mathematical proposition; a cold equation he’d had a gift for every since he could remember, every since he was a boy with a Daisy BB g*n in the backyard of t