"Sherlock--" Susan's eyes were approaching saucer-like size as she turned her attention to her uncle's weird boyfriend. "You mean he's the magic stranger?"

Although he didn't look at her, Sherlock calmly took off his watch, set it in the palm of one hand, covered it with his other palm--and then pulled his hands apart to reveal that both were empty. Which drew appreciative laughter from the adult members of John's audience and gasps from the children.