Pax, by Sara Pennypacker

War is coming and Peter is being sent to stay with his grandfather for safety.  Peter's pet fox Pax, however, cannot come and so Peter is forced to abandon him (in the heart-wrenching first chapter).  Peter immediately regrets doing so and heads off on a quest to find and rescue Pax.  Along the way, Peter befriends an embittered veteran who teaches him valuable lessons about war and helps him on his way.  And, in alternating chapters, Pax meets other foxes and learns more about his own nature and the ways of humans.

Pennypacker, who I know better for her charming Clementine series, has created a unique and haunting book.  Initially, it's a straightforward adventure, but more of an allegory about war in the end.  I felt that the story was a bit dark for children and not entirely appropriate for the middle readers it is targeted towards (in much the same way that Watership Down got mischaracterized as a children's book).  I enjoyed it, especially the chapters about Pax (who ultimately proves a more appealing protagonist than the boy) and the anti-war message is soft-pedaled but well-presented.