"All right. Looking round to make sure they weren't being watched, he huddled closer. The last thing he needed was to cause a panic. When he was sure that the coast was clear, he reached into his sleeve and withdrew a highly polished wooden stick.

The best demonstration was probably a simple spell. He didn't want to enchant any muggle electric things, they tended to react badly to magic, so perhaps a conjuring would work.

Concentrating hard, he waved the wand in a quick little arc and thought the incantation. On cue, a little blue flame erupted from the tip, one that he could safely pick up and hold in his hand. He demonstrated this, tucking the wand away and holding the little flame in his cupped hands.

"I can do more, but I need to speak to this department first," he whispered.