How does the author use foreshadowing in The Blue Girl?

In pages 250-277, the author is laying out his plot pieces in order for the final showdown between the girls, Pell-Mell, the fairies and the soul-eater's. He adds elements of Imogene's plan and lets the characters talk about their actions in a way to heighten the tension. As the reader is viewing the narrative from outside of the book the author is allowing them to see the faults and problems in the plan - that neither Imogene, Maxine or Pell-Mell have any thought of how to actually defeat the soul-eater. These elements create the suspicion that the plan will be disastrous, and foreshadows the events later in the book.