The youth Taran lives at Caer Dallben with his guardians, the ancient enchanter Dallben and the farmer and retired soldier Coll. He is dissatisfied with his life, and longs to become a great hero like the High Prince Gwydion. Due to the threat posed by a warlord known as the Horned King, Taran is forbidden from leaving the farm and charged with the care of Hen Wen, the oracular white pig. When the pig escapes, Taran follows her into the forbidden forest. After a long, fruitless chase he is attacked by a host of horsemen galloping toward his home, led by the Horned King himself. He manages to escape, but drops, wounded, to the ground. He awakes to find his wound treated by none other than Gwydion, the crown prince in Prydain's ruling House of Dôn, who has been traveling to Caer Dallben to consult Hen Wen. Gwydion, determined to find the pig, takes Taran along with him. Guided by Gurgi, a hairy humanoid living in the forest, they reach the Horned King's camp, and learn that his target will be Caer Dathyl, the home castle of the House of Dôn. Gwydion determines to warn the royal court, but the group is attacked by the powerful undeadCauldron-Born soldiers, who capture Gwydion and Taran, and take them to Queen Achren in Spiral Castle. The sorceress asks Gwydion to help her to overthrow Arawn and to join her in ruling Prydain together. When Gwydion refuses, he is imprisoned, but not in the same place as Taran. Princess Eilonwy, who lives in Spiral Castle to learn enchantment from her self-proclaimed "aunt" Achren, visits Taran's dungeon cell, and agrees to free first his companion, and then him. While travelling through a labyrinth of tunnels to join Gwydion and his horse Melyngar outside the castle, Taran and Eilonwy steal weapons from a tomb. As they emerge into the woods, Spiral Castle collapses; they later learn that this is because the weapon Eilonwy has taken is the legendary sword Dyrnwyn. Eilonwy has also misunderstood Taran's request to free his companion, for the man waiting outside is not Gwydion, but another former prisoner of the castle: Fflewddur Fflam, a king by birth but a wandering bard by choice. The three search the ruins, then mourn Gwydion's presumed death, and decide to take up his task to warn Caer Dathyl. Rejoined by Gurgi, but pursued by the Cauldron-Born, the group is driven far east of their northward course, and ends up in the underground realm of the Fair Folk, who have rescued Hen Wen. The Fair Folk's King Eiddileg grudgingly agrees to let Taran have her back, to re-equip their party, and to provide a guide, a dwarf called Doli. On their journey to Caer Dathyl, against Fflewddur and Doli's advice, Taran rescues an injured fledgling gwythaint, one of the great birds of prey that Arawn has enslaved. The gwythaint recovers quickly and escapes overnight, shortly followed by Hen Wen, who flees just before the Horned King's army spots them all. Fflewddur, Doli and Gurgi stand to fight, while Taran and Eilonwy go ahead on Melyngar chased by the Horned King. On the top of a hill, he attacks them, and breaks the boy's sword on the first blow. Taran seizes Dyrnwyn from Eilonwy, but lacks the "noble birth" needed to draw it. White flame burns his arm, and throws him to the ground. Just before losing consciousness, he sees another man in the trees and hears an unintelligible word. The Horned King's mask melts and he bursts into flame. When Taran wakens in bed, he learns that the man who destroyed the Horned King was Gwydion, who had been with Achren at another stronghold when Spiral Castle fell. After withstanding Achren's torture, he has learned to understand the hearts of all creatures, and was able to communicate first with the gwythaint, and then with Hen Wen. From the oracular pig he learned how to destroy the Horned King, by saying his secret name. Recognizing his nobility, Eilonwy has given Dyrnwyn to him, while Taran and his companions are to receive treasures from Caer Dathyl in recognition of service to the House of Dôn. Eilonwy gets a ring made by the Fair Folk, Gurgi a wallet of food that cannot be depleted, Fflewddur a golden harp string that can never break, Doli the ability to turn invisible. Taran—who in the course of his adventures has realized that Caer Dallben is where he most wants to be—asks only to return home. Gwydion accompanies him back to Caer Dallben, along with Eilonwy and Gurgi, who take up residence there as well.
Reception
In 2012 The Book of Three was ranked number 18 among all-time best children's novels in a survey published by School Library Journal, a monthly with primarily U.S. audience. Ruth Hill Viguers of The Horn Book Magazine said the book would "wear well, and that children will be eager for other stories in which Taran may yet learn the meaning of heroism. The Junior Bookshelf criticized the supporting characters, the contrived and excessive use of humor, and the heavy-use of lessons. Margery Fisher in Growing Point, criticized the novel for being too derivative of Tolkien, Garner, Masefield, and T.H. White and that, "perhaps with only one of these models or influences, it would be better". The Times Literary Supplement called the novel "a very fine fantasy-adventure", admitting that the book does not compare to the works of Tolkien, but has "quite a compelling magic of its own". The School Library Journal called the novel, "one of the most iconic and influential works of middle-grade fiction from the 20th century," which "helped pave the way for countless fantasy adventures."
Adaptations
The Book of Three and its successor The Black Cauldron were loosely adapted by Walt Disney Productions and released in 1985 as Disney's 25th animated feature film, under the latter title. Gross receipts for The Black Cauldron did not match its production costs, commercially a great failure. Lloyd Alexander's reaction was twofold: "First, I have to say, there is no resemblance between the movie and the book. Having said that, the movie in itself, purely as a movie, I found to be very enjoyable."
