Taran Wanderer is the fourth book in the Chronicles of Prydain series by Lloyd Alexander. It tells of Taran's search for his lineage through which he encounters many different people who each help to shape Taran as he learns about who he truly is. It is the only book in the series in which Princess Eilonwy does not appear, though she is referenced frequently. It is also the only book in the series in which Prince Gwydion does not appear.
After the events depicted in The Castle of Llyr, the Assistant Pig-Keeper Taran returns to Caer Dallben, leaving Eilonwy in the island Kingdom of Mona for "royal training". Taran grows depressed and restless in Eilonwy's absence as he struggles internally with his (now fully realized) love for the golden-haired princess. Since Taran has no knowledge of his parents (whether noble or common) he feels that he cannot act upon his wish to marry Eilonwy upon her return. Therefore Taran sets out on a quest to settle the question of his birth once and for all.
Accompanied by his eternally loyal friend Gurgi, Taran sets out for the Marshes of Morva in the hopes that the witches Orddu, Orwen and Orgoch (whom he last encountered in The Black Cauldron) will reveal to him the nature of his birth. Consistent with their characters, the witches will only bargain for the information that Taran desires. However, owning few possessions of any significant worth, Taran is unable to barter for the knowledge of his parentage. As an alternative, the witches tell him of the legendary Mirror of Llunet hidden away in the far off Llawgadarn Mountains. The mirror, the witches claim, will provide Taran with the answer he seeks.
Departing the Marshes of Morva, Taran journeys to Cantrev Cadiffor, the realm of King Smoit, who met and befriended Taran in The Black Cauldron. There, Gurgi and Taran meet the farmer Aeddan, who shelters the two after they run afoul of Lord Goryon's outriders, who steal Taran's horse, Melynlas. His night in the care of the farmer and his wife gives Taran a new perspective on honor, and he earns a greater respect for the common folk of Prydain. Taran and Gurgi set out next to the home of Lord Goryon in order to reclaim Melynlas and Gurgi's pony, and after succeeding, proceed to the stronghold of Lord Gast, where they meet their old friend Fflewddur Fflam who, having once again grown weary of his own kingdom, has taken to roaming Prydain as a wandering bard. Both Gast and Goryon are quick to extol virtues that they don't actually have; in fact, the virtues they extol most heartily are the ones in which they are most obviously lacking. Following this, the three reunited companions go to Smoit's castle, where Smoit welcomes them heartily.
The next morning, word from Lord Gast arrives that the Lord Goryon has stolen his prize cow, Cornillo. Goryon and Gast have been fighting over Cornillo for so long that neither remembers which one of them originally owned her. Furious at the disturbance of peace in his kingdom, Smoit immediately sets out to apprehend the two Lords with a dozen men in tow whose numbers include Taran, Gurgi and Fflewddur. Smoit, however, falls into a river and is rendered unconscious. Taran saves the king, who in turn is willing to listen to Taran's proposal for how to deal with the two warring cantrev lords. Previously, Smoit intended to simply throw Gast and Goryon in the dungeon, a punishment which the two have endured on numerous occasions in the past. Taran suggests that the rivals be forced to resow the crops of the farmer Aedden, whose lands have been destroyed in the conflict. Meanwhile, the two herds of cows which have become hopelessly entangled will be divided into equal halves by Goryon, with Gast getting to choose which half he will take for himself. Cornillo will go to Aeddan to stop the feuding between the two lords, and as further compensation for the damage done to Aeddan's crops.
After returning to King Smoit's castle, Smoit takes Taran aside and admits that he isn't the most quick witted of kings and that he admires Taran's good sense. Furthermore, he tells Taran that he is a widower with no heir, and longs for a son just as much as Taran longs for parentage. Smoit offers to adopt him, so that Taran would succeed Smoit as King of Cadiffor. Taran considers it, but refuses, believing that Eilonwy would not respect him if he abandoned his quest to find his parentage after it had barely begun. But, he says that if he finds out that he is of noble birth on his journey, he will gladly accept Smoit's offer.
After leaving King Smoit, Taran's pet crow, Kaw, returns to him with news of Princess Eilonwy's continued annoyance at her forced training. When Kaw plays one of his pranks with Flewddur, the companions find a small casket with a piece of bone inside, which Taran keeps. Llyan then surprises her bard with a 'gift' of a frog which is quite nearly dead. They are about to cast it aside, but at feeling a slight heartbeat, Taran entertains the thought that the frog may have life left in him yet. When the frog makes some rather peculiar noises which sound suspiciously like "Gurgi", "food", and "help" followed by another sound which we may only assume is 'Humph,' the companions realize that they have found Doli. Taran loses no time in reviving the frog with water from a flask.
Doli then tells them of his encounter with the wizard Morda, the reason for his enchantment. Morda had not only managed to find a way to enchant the fair folk, but also to break into their realm as well, something which had previously been unthinkable. Taran, Gurgi and Flewddur set off to rectify the situation, but quickly fall into Morda's traps. Morda, who has nothing but scorn for all of mankind, turns Gurgi and the bard into animals and is about to do the same with Taran, but he fails - the bone piece the companions have found actually contains Morda's life-force. Then Llyan intervenes and with her help, Taran manages to kill the wizard. During this adventure together, the companions learn that Morda allowed Eilonwy's mother Angharad to die when she had begged for shelter during her search for her infant daughter; the source of his power came from the magical amulet she had worn. The book of spells, which she had with her and which had proved pivotal in The Castle of Llyr, Morda had given to Glew when the latter had sought to be a great sorcerer.
When Doli and the companions are ready to part, Taran gives Angharad's amulet to the Fair Folk (to whom it had originally belonged), and Doli happens to identify the horn Taran had received from Eilonwy as a magical calling device, capable to summon help from the Fair Folk once only. After parting with Doli, Taran, Gurgi, and Fflewddur make camp with the mercenary Dorath and his mob. However, while Dorath is initially friendly, his true amoral nature is revealed the following morning. Taran and Dorath fight, and Dorath cheats by pulling a knife. Dorath steals Taran's blade, and the latter takes a while to convalesce.
The party later finds themselves at the farm of Craddoc, an old shepherd whose land has fallen into disrepair who claims to be Taran's real father. Now feeling a commitment towards helping Craddoc, Taran and Gurgi remain with Craddoc, giving up the quest for the Mirror of Llunet. They tirelessly work for many months at his farm helping him out, and Taran and Craddoc form a bond together. However, Taran continually scorns Craddoc for robbing him of his dreams of noble birth. Later, during the winter time, Craddoc suffers a bad fall down a mountain gorge, and despite Taran summoning help with Eilonwy's horn, Craddoc soon after passes away, revealing to Taran before his death that he had lied to Taran in hopes of gaining his help in restoring his land, and that he was not his real son.
After Craddoc's death, Taran and Gurgi begin a long journey throughout the Free Commots, where Taran works with three of the best crafters of Prydain in hopes of finding a trade for him to make his own way in the world. His first teacher is Hevydd the Blacksmith, who guides Taran through the making of a new sword to replace the one that was stolen from him. The final blade he crafts is dented and scarred, but the blade itself is very strong. The next teacher is Dwyvach Weaver-Woman, who instructs him in the art of weaving cloth. His training with her results in a brand-new cloak and a deeper understanding of patterns. His final teacher is Annlaw Clay-Shaper, one of the most revered potters in all of Prydain. Though he tried hard to learn from Annlaw, Taran found that the skill of pottery eluded him, and after venting his frustrations to Annlaw, is told he has gained a very valuable treasure: humility. His attempts at pottery lead to Taran creating a bowl he would later present to Eilonwy as a gift in The High King.
It is through Annlaw that Taran learns where the Mirror of Llunet is. After a short journey, he arrives at the Mirror, a pool of water at the mouth of a cave, and gazes into it. Shortly after, Dorath appears with Taran's old sword and, thinking that it contains treasure, destroys the Mirror. Once again they clash swords, but this time Taran's new sword is able to shatter his old one and disarm Dorath. Dorath flees from the cavern, but Taran does not pursue.
Taran later relates to Annlaw what he saw in the Mirror. It showed Taran his own reflection and nothing more. In that moment of reflection, however, Taran saw everything he had become after all he learned in his wandering. Taran was no longer the boy he started out as; now, through all he endured on his long journey of discovery, he sees himself as a man.
- Tuck, Donald H. (1974). The Encyclopedia of Science Fiction and Fantasy. Chicago: Advent. p. 6.