The Horse and His Boy by C.S. Lewis is not my very favorite of the Narnia books, but it always ranks in the top three. Unlike other Narnia books, this book does not feature characters traveling from our world to Narnia, but is set in Narnia throughout. Shasta, a young slave boy in a seaside town in Calormen, escapes being sold to a cruel master by running away with that very man's prize warhorse -- a Narnian Talking Horse, though the cruel master didn't know it. On their way, Shasta and the horse Bree meet up with Aravis, a high-born Calormene girl, and her own talking horse Hwin. Together, the four companions face the dangers of the city and the rigors of the desert, foil a secret plan for a Calormene invasion of Narnia, and discover the secret of Shasta's heritage.
If you've never read the Chronicles of Narnia, this is not the obvious place to start. (I always recommend starting with The Lion, the Witch, and the Wardrobe.)
This book actually takes place during the period of time covered in the
last chapter or so of LWW, in the geographical region south of Narnia.
It has plenty of adventure and humor (Bree, the proud warhorse, is often
unintentionally funny), really good characters (if you're looking for a
strong female lead, Aravis is probably the best the series has to
offer), and a great scene between Shasta and Aslan near the end.
been reading the Chronicles of Narnia with my young cousin for the past
two years. I hold to the original publication order, so we have
finished five books now, with two still to go. We read them
sporadically, whenever I come for a visit, so there are sometimes gaps
of a couple months in between chapters (I try to find good stopping
places, and have gotten pretty good at summarizing and recapping before
starting up again). I remember listening to my dad reading the books to
me when I was about my cousin's age, and I want to pass that experience
(Reviewed from my personally purchased copy.)