How does the author use foreshadowing in Blankets: An Illustrated Novel?

Craig's experiences at church camp are no better than they are at school, which surprises and disgusts Craig. Things are bleak until he meets Raina, a beautiful 17-year-old girl from Michigan. Craig and Raina spend as much time together as possible. Craig's dissapointment with camp foreshadows his dissapointment at the end of his relationship with Raina.