How does the author use foreshadowing in the book, Fairy Tale: A Novel?

Bowditch’s shed is a location of magic and suspense. King foreshadows from the beginning of the novel that there is something about the shed that is not right. This sense is strengthened when Charlie hears something skittering around inside the shed, and then again later when Bowditch goes into the shed and shoots something that has become trapped in it.

After Bowditch dies of a heart attack, Charlie learns that the shed protects the opening to the land of Empis. Charlie and his father later cover the opening of the well with concrete to protect it from exploitation.