Young Shasta grew up in Calormen, but always felt a drawing towards the north. When a nobleman rides up one day, and begins negotiating with Shasta's father to buy him, he learns that he is really a foundling from Narnia. Shasta wants to escape, and opportunity presents itself, when the nobleman's horse begins to talk to him! It seems that Bree was also stolen away from Narnia, so the two form an alliance and head north. But there are many adventures and surprises along the way. Plus, it seems that somebody has their eye on Shasta!
I love this book! I gather that there is some disagreement as to the order in which you should read the Chronicles of Narnia, but this one is well placed at #3, falling as it does during the later stages of the High-Kingship of Peter. This book has a wonderful Arabian Nights feel to most of it, and it is filled with adventure and suspense. I enjoyed reading this book to my children, and they enjoyed hearing it. We all recommend this book to you!