Professor Burbage was not put out in the slightest. "Would you mind if I, if I touched it?"

Relieved that she was at least direct about it, Snape reached into a pocket in his robes and drew out an honest-to-goodness muggle wallet. Burbage went into ecstasies. Snape was ready to stand up and leave the Great Hall right there, but restrained himself, pulled the little plastic card out, and handed it to her. She examined every detail with great eagerness.

"How does it work?" she asked, adding a few seconds later, "If you don't mind my taking up your valuable time."

"Not at all. Do you see this dark stripe on the back? It's a magnetic strip that can be read by some kind of computer. I can insert the card into a computer terminal in a wall, enter a secret code, the computer checks whether or not I have money in my account, and if I do, it will give me some of that money, deducting the sum from my account. Instant cash, twenty-four hours a day. The whole process takes less than two minutes. Much nicer than a nasty rough ride in a nasty old cart through dark underground passages."

Burbage studied the card with greater respect. "What's the secret code?" she asked.

"A secret," Snape replied, retrieving his card and replacing it in his wallet.

She blushed crimson, a rather attractive color on her otherwise plain features. "That was rude of me," she said. "Do you think I might ever watch you use it?"

"You'd have to visit London with me. There aren't any bank teller machines in Hogsmeade."

"They say you… frequent restaurants. And go to… movies."

"From time to time. Plays and bookstores, too. If you joined me one evening, you could probably claim the whole excursion as work-related and get overtime for it."

"What's overtime?" Burbage asked, then giggled at the expression on his face. "Seriously though, I may take you up on the trip to London some time."