Crispin: The End of Time by Avi

As long as I could keep myself out of bondage, I would be true to Bear's teaching. And so it was that beyond all else, I was determined to keep my freedom.

After the death of their beloved mentor, Bear, Crispin and Troth are more desperate than ever, wandering the desolate French countryside, where they don't speak the language and know no one. The only hope they cling to is that somehow they can reach Iceland, where Bear had said there were no kings or lords, and where they can live in freedom. Crispin is determined to fulfill this dream, both for himself and to honor Bear's memory. But the road to liberty is filled with danger, betrayal, and loss. Crispin must decide for himself what freedom really means—and how high a price he is willing to pay for it.