If THE BOOK OF THREE is about Taran's impetuous immaturity and the continuous mistakes he makes, THE BLACK CAULDRON is about how Taran begins to learn to deal with others. His biggest challenge is Ellidyr, a nasty, spiteful, mean-spirited person who acts as a mirror, forcing Taran to look at and overcome his own worst tendencies.
In the end, Ellidyr turns it around and makes the ultimate sacrifice by jumping into the cauldron to destroy it. "He has lost all else, even his steed."
"Or perhaps gained all," Gwydion answered. " And his honor shall be certain." Gwydion goes on to say that a barrow will be raised for Ellidyr, and also for Morgant, who switched sides at the end and who would have used the cauldron for ultimate power. Taran is incredulous that Gwydion would honor Morgant.
"It is easy to judge evil unmixed," replied Gwydion. "But, alas, in most of us good and bad are closely woven as the threads on a loom; greater wisdom than mine is needed for the judging...I honor Morgant for what he used to be, and Ellidyr for what he became."
I had hoped for all five books of the Prydain Chronicles in the 48 Hour Reading Challenge Weekend, but two will have to do. The other three will go with me to Colorado.