The boy shrugged. "I've forgotten it," was all he said. And then, "I guess I wasn't taught well enough." - Jonathan Stroud

Spy three suspicious butterflies flitting over hedge. Check the planes. Yep, small foliots, arms flapping wildly. Wasp rises up behind them, shoots down out of sun, zaps them with Infernos, one, two, three. Burning butterflies crash-land in pond. Alert master to my triumph. She inspects charred fragments. Her scowl deepens; turns out they were her slaves, returning with valuable information.

I order you, Bartimaeus, to reveal whether you have diligently and wholly carried out your charge-" "Of course I have - what do you think this is, costume jewelry?

Perhaps he'd want me to conjure up an illusion. That might be fun: there was bound to be a way of misinterpreting his request and upsetting him†.