Cauldron-Born who have discovered him on the mountain, he rolls a rock at them, and discovers Dyrnwyn in the hollow the stone occupied. Wielding Dyrnwyn, Taran slays the undead warrior who approaches to slay him, and at that instant all of the Cauldron-Born die as one. Taran's group enters the fray, and the battle continues through the halls of Annuvin. Taran is almost deceived by Arawn - who has taken the guise of Gwydion - into giving up the sword. After the chaotic defeat of Arawn's forces, the companions gather before the Great Hall. Achren identifies Arawn in the form of a nearby serpent preparing to strike Taran and grabs him. He strikes her fatally, but Taran kills him with Dyrnwyn. With the death of Arawn, the stronghold of Annuvin bursts in flame and falls in ruins, destroying all of the magical implements inside; only Gurgi manages to save several scrolls containing knowledge of farming, smithing, and other crafts. The sword Dyrnwyn begins to fade, losing its magic. The allies travel to Caer Dallben, where Gwydion tells them that in victory the Sons of Don, with all kinsmen and kinswomen, must return to the Summer Country. Indeed, all those who still have magic will depart, and the Fair Folk and Medwyn have closed their realms to outsiders. Dallben and Eilonwy must also go, and others who have served well, Taran among them, are given the chance to accompany them. Taran proposes to Eilonwy at last, and she accepts. The Sons of Don plan to leave the next day. However, Taran becomes uncomfortable about his decision overnight. The witches Orddu, Orwen and Orgoch appear before him and reveal that they too are departing, and leave him with an unfinished tapestry depicting his life. He realizes there is much work to be done to rebuild Prydain, and he has made many promises; so he determines to remain behind. Eilonwy is able to willingly give up her magical nature in order to remain with him, and the two are married. Dallben reveals that with this last quest, Taran has completed a path prophesied in the Book of Three whereby an orphan of "no station in life" would succeed the Sons of Don as High King. Dallben had traveled to seek such a one and try to hasten the day of Arawn's defeat; on this journey, he found a baby, hidden in the trees