Diana Wynne Jones said this quote

“ He gave Sophie the smile which had no doubt charmed the Witch of the Waste and possibly Lettie too, firing it along the fork, across the cream, straight into Sophie’s eyes, dazzlingly. “If you can bully Calcifer, the King should give you no trouble at all.” Sophie stared through the dazzle and said nothing. This, she thought, was where she slithered out. She was leaving. It was too bad about Calcifer’s contract. She had had enough of Howl. First green slime, then glaring at her for something Calcifer had done quite freely, and now this! Tomorrow she would slip off to Upper Folding and tell Lettie all about it. ”