If THE CHANGELING was The Book of my childhood, this was The Book of my teen years:
What it's all about:
Jan is the son of the prince of the unicorns. Though he's desperate to prove his worth to his father, his curious and mischievous nature cause enough trouble that his father has held him back from the Pilgrimage, when the colts and fillies join the Ring of Warriors on a journey to their homeland and become full members of the ring themselves. This year, despite a terrible mistake, Jan is allowed to come. But his father has feared for good reason. For in the caves near the sacred well lives the enemy that drove the unicorns from their home ages ago; an enemy that is waiting for Jan, eager to use him to destroy his people once and for all.
Why it is awesome:
I am not a unicorn person; I have always been far more fond of dragons and griffins and the like. But Pierce's unicorns are no dainty ponies-with-horns--they are warriors and sages, with a culture more fully developed than most human societies you'll find in fantasy books. And all of it is beautifully told, with clear but poetic prose that gives the book a mythic feel. At the same time, the characters and their conflicts, both internal and external, are intensely real. It's a pleasure every time I follow Jan on his journey.
Sadly I cannot recommend the rest of the trilogy the same way. But don't let that stop you from checking this one out! It stands alone quite well. (And I should know--the second and third books were out of print until a few years ago, and during my teen years I didn't even realize there were sequels.)