Very interesting read over all. Gives you a look at the Crusades from a viewpoint near some of the battles, but not overly focused on the war itself. Nice bit of 'historical' without dropping massive details on one. And, for a young adult book, thats not a bad thing.
My only real complaint would be the end of this story doesn't really 'finish' up. We know the 'general' ending, more if you know anything of that period of history, but for the main character himself. . .there is no wrap-up of any sort. We don't know if he goes back to England or returns to his old home. NOTHING is said about what becomes of him after the story. . .which is really quite annoying.
Granted, this is the third book of a series, and while the story generally stands alone - it may or may not continue in the next book. As this is the only book I have ever seen by this author, I have no way of telling how it fits in with the overall series.