Diana Wynne Jones. Howl's moving castle (№ 378300)

First, always read the recipe from beginning to end and very carefully. Much will become clear already by the manner of presentation: understand what a curse - self-executing, self-running, a simple verbal spell or enchantment of the "word and deed". Then again all re-read and think about what stages you play, and what is inscribed for greater mystery. Now we're already engaged in a strong enough spell. Soon you will realize that during any kind of fascination there are always deliberate errors or ambiguity.