How does the author use foreshadowing in Peter and the Shadow Thieves?

Chapter 13 establishes the existence of the box of starstuff that is the main object of Lord Ombra's search. It also provides a turning point for Peter when he overhears Ombra speaking about Molly Aster and her family. He decides he must leave the island and go to England, foreshadowing the middle portion of the book which will take place on the journey between the island and England.