The horse, Bree, and his boy, Shasta are fleeing their slavery, heading north to Narnia and freedom. Along the way, they join the horse, Hwin, and her girl, Aravis, who is fleeing an arranged marriage. Together they ride north across the desert. Meanwhile, the vengeful Calormen prince Rabadash determines to destroy Archenland and invade Narnia to capture Queen Susan and make her his bride.
When Shasta and Aravis discover his plan they must warn Archenland in time, or all is lost. Their journey to "Narnia and the North" involves difficult and dangerous situations, through which they come to realize that they are being guided by none other than Aslan himself! The surprise that awaits Shasta at the end of his journey is more than he ever dreamed of!