The Horse and His Boy
by C. S. Lewis
A boy named Shasta overhears Arsheesh the fisherman negotiating to sell him to a powerful Calormene feudal nobleman. He is relieved to discover that Arsheesh is not his real father, since there was little love between them. While Shasta awaits his new master in the stable, Bree—the nobleman's stallion—astounds Shasta by speaking to him. Bree is a Talking Horse from Narnia who was captured by the Calormenes as a foal. He tells Shasta that the nobleman will treat him cruelly, and Shasta resolves to escape. The horse suggests that they ride north together to the land of Narnia. On their journey, Shasta and Bree meet another pair of runaways: Aravis, a young Calormene aristocrat, and Hwin, a Talking Horse. Aravis is running away to avoid being forced to marry Ahoshta, the Grand Vizier of Calormen, while Hwin's story is much like Bree's.
The four runaways travel through Tashbaan, the great capital of Calormen. There, they encounter Narnian visitors who mistake Shasta for Corin, a prince of Archenland, who went exploring earlier that day. Obliged to accompany them, Shasta overhears the Narnians' plans to escape from Calormen to prevent a forced marriage between Queen Susan and Rabadash, son of the Tisroc (or king) of Calormen. Shasta escapes when the real Prince Corin returns.
Meanwhile, Aravis has been spotted by her friend Lasaraleen. She asks Lasaraleen to help her escape from Tashbaan. Lasaraleen cannot understand why Aravis would want to abandon the life of a Calormene noblewoman or refuse marriage with Ahoshta, but she helps Aravis escape through the garden of the Tisroc's palace. On the way, they hide when the Tisroc, Rabadash, and Ahoshta approach. Aravis overhears the Tisroc and Rabadash discussing the Narnians' escape. Rabadash wants to invade Narnia to seize Queen Susan. The Tisroc gives Rabadash permission to conquer Archenland before making a quick raid into Narnia to kidnap Queen Susan while High King Peter is away battling giants in the north.
Aravis rejoins Shasta and the horses outside Tashbaan and tells them of the plot. The four set out across the desert, and a lion (whom they later discover to be Aslan) frightens them into fleeing swiftly enough to outrun Rabadash's cavalry. Shasta arrives in Archenland in time to warn Archenland and Narnia of the approaching Calormenes. When Rabadash and his horsemen arrive at the castle of King Lune in Archenland, they find the defenders alerted. A siege ensues. There is no clear outcome until reinforcements from Narnia, led by Edmund and Lucy, arrive. The Calormenes are defeated, and Rabadash is captured.
Rabadash rebuffs King Lune's offer of a conditional release. Aslan the Lion, the King of Beasts, son of the Emperor-Over-the-Sea, the King above all High Kings in Narnia, arrives in Archenland. After Rabadash insults Aslan, he is transformed into a donkey. Aslan informs him that his true form will be restored if he stands before the altar of Tash at the Autumn Feast; thereafter, however, the prince will become a donkey permanently if he ever ventures more than ten miles from the Temple of Tash. For this reason, Rabadash pursues peaceful policies when he becomes Tisroc, as he dares not cross the ten-mile boundary by going to war.
The victorious King Lune recognizes Shasta as his son Cor, the long-lost identical twin of Prince Corin and—as the elder of the two—the heir to the throne of Archenland. Cor had been kidnapped as a baby in an attempt to counter a prophecy that he would one day save Archenland from its greatest peril. Shasta's timely warning of the Calormene attack has fulfilled the prophecy. Aravis and Shasta live in Archenland thereafter and eventually marry. Their son, Ram, becomes the most famous king of Archenland.