The second book in Lloyd Alexander's
Chronicles of Prydain, a five-volume fantasy series inspired by Welsh mythology, opens at the small farm of Caer Dallben in the land of Prydain. Taran, a young man who serves as Assistant Pig-Keeper to the ancient enchanter Dallben, is washing the oracular pig Hen Wen when Prince Ellidyr Son of Pen-Llarcau arrives and insults him as a "pig-boy." Soon Gwydion Son of Don, the greatest war leader in Prydain, arrives and summons a council. Friends and allies gather, including Fflewddur Fflam, a bard whose enchanted harp strings snap whenever he exaggerates; Doli, a dwarf of the Fair Folk who can turn invisible; Adaon, the noble son of the Chief Bard Taliesin, who wears a curiously shaped iron brooch; and two kings, Smoit of Cantrev Cadiffor and the hawk-faced Morgant of Madoc. Also present are Princess Eilonwy, a sharp-tongued girl who lives at the farm; Coll, Dallben's stout warrior companion; and Gurgi, a shaggy, loyal creature devoted to Taran.
Gwydion reveals that Arawn, the Death-Lord who rules Annuvin, the Land of Death, has been expanding his army of Cauldron-Born, deathless warriors created by steeping the bodies of the slain in a magical cauldron. Gwydion plans to attack Annuvin, seize the cauldron, and destroy it. Three bands will approach Dark Gate, the twin mountains guarding Annuvin's entrance: Gwydion's strike team, Morgant's diversionary horsemen, and a rearguard led by Adaon with Taran and Ellidyr. Before departing, Dallben gives Taran a finely crafted sword whose only powers are those of its wielder.
The company rides out, leaving Eilonwy and Gurgi at Caer Dallben. Along the way, Adaon shares troubling dreams: he saw Ellidyr carrying a black beast on his shoulders and Taran filled with grief, but he refuses to say what he dreamed of himself. On a narrow trail, Ellidyr jostles Taran's horse Melynlas off the path, then saves both Taran and the horse with astonishing strength. When Gwydion demands an explanation, Taran takes the blame.
Near Dark Gate, Eilonwy and Gurgi appear, having followed the company. Then comes urgent news: The assault succeeded, but the cauldron is gone, stolen from Annuvin days earlier by someone unknown even to Arawn. Gwydion orders a retreat to Caer Cadarn, King Smoit's stronghold. Before the companions can regroup, Huntsmen of Annuvin ambush them. These mortal warriors are bound by blood oaths to Arawn and bear crimson brands on their foreheads; killing one only strengthens the survivors. Ellidyr saves Taran's life during the attack, and Adaon leads a breakout. The companions escape westward to a hidden Fair Folk way post kept by Gwystyl, a gloomy creature whose pet crow Kaw croaks the names "Orddu! Orwen! Orgoch!" Under pressure, Gwystyl reveals the cauldron is held by three mysterious beings in the Marshes of Morva.
A debate erupts over whether to return to Gwydion or press on to Morva. When Ellidyr declares he will go alone, Taran chooses the Marshes. Adaon, who commands the group, defers to Taran's decision, and all companions follow. During the westward journey, Adaon finally reveals his own dream: a warm, sunlit glade with birds and flowers, even in winter. Taran is relieved, not recognizing the dream's true meaning. Adaon privately tells Taran that should anything befall him, his most treasured possessions, especially the iron brooch given to him by his betrothed Arianllyn, should pass to Taran.
Ellidyr soon deserts the group to seek the cauldron alone. Shortly after, Huntsmen attack. A Huntsman hurls a dagger at Taran; Adaon rides between them and takes the blade in his chest. The companions carry him to a sheltered glade, warm and sunlit, exactly matching his dream. Adaon explains he dared not reveal his fate lest the choice to turn back be made from cowardice. He presses the brooch into Taran's hand and dies.
The companions bury Adaon and press on. Taran discovers the brooch has sharpened his perception, granting prophetic dreams and heightened senses. Following these gifts, he finds Fflewddur, who was separated from Doli during the last battle. A gray marsh bird guides the companions to Morva, where pursuing Huntsmen follow them into the bog and perish in quicksand as Taran navigates a hidden chain of submerged islands revealed in his dreams.
Beyond the marsh, they find the cottage of three enchantresses: the plump, sharp-eyed Orddu; Orwen; and the hooded, sinister Orgoch. At the mention of Dallben's name, their hostility vanishes; they fondly recall raising him from a baby found in the marsh. They confirm they possess the Black Crochan, their name for the cauldron. Arawn borrowed it but broke his oath to return it, so they reclaimed it. They refuse to surrender it.
Gurgi discovers the Crochan hidden under straw in a chicken roost. That night, the companions try to carry it away, but their hands stick fast. Orddu, amused, offers to sell the Crochan but rejects every treasure the companions offer. Finally Taran offers Adaon's brooch, which Orddu reveals was fashioned by Menwy, first of the bards, and filled with dreams and vision. She warns it must be given willingly. Anguished but resolute, Taran surrenders it. The enchantresses also reveal the only way to destroy the Crochan: a living person must climb in willingly, knowing they will die.
The journey to bring the Crochan to Caer Dallben is grueling. Without the brooch, Taran's heightened senses vanish. Eilonwy consoles him, saying the brooch's powers came from the clasp, not from within him. At the River Tevvyn, the Crochan lodges between boulders and Fflewddur breaks his arm in the crossing. Ellidyr reappears, battered and starving, having never reached Morva. Consumed with jealousy, he offers his strength to free the Crochan only if the companions swear he alone found and won it. With gwythaints, Arawn's winged scout creatures, circling overhead, Taran reluctantly agrees. Ellidyr frees the Crochan but grows paranoid, attacks Taran, and flees with the cauldron and all three horses.
On foot, the companions encounter King Morgant, who reports Gwydion and Coll are safe. Morgant's men captured Ellidyr, who claimed the Crochan as his own and the companions dead. When Eilonwy reveals the truth, Morgant leads them to his camp and reveals his treachery: He intends to use the Crochan to create a Cauldron-Born army and seize all Prydain. He has the companions bound, threatening to slay them and cast them into the cauldron. He offers Taran a position as war-leader; Taran refuses. Through the night, the companions struggle against their bonds. Ellidyr, conscious and remorseful, admits the black beast of pride has been a harsh master.
At dawn, Doli, who has been invisibly tracking events, frees the companions. Ellidyr, gravely wounded, charges toward the Crochan, fights through Morgant's warriors, and flings himself into its mouth. The Crochan shatters with a thunderclap. King Smoit bursts from the forest with reinforcements, followed by Gwydion and Coll. In the ensuing battle, Smoit kills Morgant. Gwystyl, whose cowardly demeanor was a deliberate disguise, had brought the intelligence that enabled the rescue.
Ellidyr's faithful mare Islimach stands over her master's body, then leaps to her death in a ravine. Gwydion orders barrows raised for Ellidyr, Islimach, and Morgant, explaining that in most people good and bad are closely woven: He will honor Morgant for what he once was, and Ellidyr for what he became. As the companions ride homeward, Taran tells Gwydion his sacrifice of the brooch was the least price paid. Gwydion replies that this is exactly why the sacrifice was so difficult: Taran chose to be a hero not through enchantment but through his own manhood. Gwydion departs to bring word to King Math at Caer Dathyl. Taran turns toward his waiting friends; Eilonwy calls out that Hen Wen will be wanting her bath, and Taran gallops toward them.