Crispin The End of Time #3 by Avi

My twelve year old read this book to himself.  We listened to book #1 in this series so my oldest wanted to read the entire trilogy. 
Avi and Troth are alone in the French countryside, trying to remember what their beloved mentor Bear taught them.  Their goal?  Reach Iceland.
My son said the ending was ok . . .the reader has to infer what happened and he wanted to know more!!  He really liked the story, though.
-Borrowed from the library.