Two days after Notre Dame burned, I flew to Paris to appear on the TV programme La Grande Librairie for a discussion about cathedrals. The following morning I had breakfast at the Hotel Bristol with my French publisher and she asked me to write a short book about Notre Dame and what it means to all of us. She said she would donate the publisher's profits to the rebuilding fund and, if I wished, I could do the same with my royalties. Yes, I said; of course, I'd love to.