The Horse and His Boy by C.S. Lewis

Narnia…where horses talk, where treachery is brewing, where destiny awaits.

On a desperate journey, two runaways meet and join forces. Though they are only looking to escape their harsh and narrow lives, they soon find themselves at the center of a terrible battle. It is a battle that will decide their fate and the fate of Narnia itself.

This was the fifth book written in The Chronicles of Narnia. It now stands as the third book in the series.