Filling the scores were Mr. Zorn’s characteristic jitteriness and scratchy energy, a sense of slightly satanic mischief.

William’s mood, and Anders’s, too, which initially seemed like excitement, had surpassed excitement, and even gleeful jitteriness, to become real fear.

“It’s such a clean-burning experience that you don’t have that jitteriness or muscle aches or other physiological consequences of consuming so much caffeine.”