How did one spend a million pounds for the good of humanity?

I asked myself, and not for the first time. Of course it would be easy to top up Neils missionary funds. That might be for the good of orphans, lepers, and the like, but what would that do for humanity? And surely the professor would be expecting more of me. All you need, Jenny, he’d said, is another challenge, a big challenge and your imagination. I had the challenge all right. He’d seen to that. But did I have the imagination equal to the challenge?