"I want your word as a witch," he said, leaning over her. "I want it binding."

He heard a distant gasp from a maid at his audacity. What he wanted was for her own magic to bind her to that agreement.

"Think of that last bit as enlightened self-interest," he told her. "Because as it stands right now, your gold will become worthless within five years, and that's an optimistic estimate. The gold you were going to give me will make excellent seed money for something much more permanent and lucrative."

Scrooge was incredibly well-informed. He'd given himself better than a university degree during all those many hours reading between customers along with dealing with local finances. He had a strong head for business but not much money for investment.