Diana Wynne Jones said this quote

“ Is something the matter?” Calcifer asked. “Yes. My heart. There was a scarecrow at the door!” Sophie gasped. “What has a scarecrow to do with your heart?” Calcifer asked. “It was trying to get in here. It gave me a terrible fright. And my heart—but you wouldn’t understand, you silly young demon!” Sophie panted. “You haven’t got a heart.” “Yes I have,” Calcifer said, as proudly as he had revealed his arm. “Down in the glowing part under the logs. And don’t call me young. I’m a good million years older than you are! Can I reduce the speed of the castle now? ”