This is the story of an adventure that happened in Narnia and Calormen and the lands between, in the Golden Age when Peter was High King in Narnia and his brother and his two sisters were King and Queens under him. It is during this glorious era in Narnian history that Shasta, a young boy living in Calormen with a cruel man who claims to be his father, dreams of traveling to the unknown North. One night he overhears his "father" offering to sell him as a slave, and Shasta decides that now is the time to begin his journey. When he meets Bree, a Talking Horse of Narnia who is a slave himself, the two decide to escape together. The pair soon encounters Aravis, a high-born girl escaping a forced marriage, and Hwin, another Talking Horse. The travelers must combine their wits and all their strength to reach the freedom they long for. And when they discover a Calormene plot to conquer Narnia, they must also race against time. The battle that ensues matches in excitement any of the adventures described in C.S. Lewis's previous two books of "The Chronicles of Narnia".
Assisted by the majestic Aslan, the Kings and Queens of Narnia, first introduced in "The Lion, The Witch, and The Wardrobe", once again rise to the occasion to defend their kingdom.