The Radiant Road — Katherine Catmull

A gorgeously woven tale of magic, friendship, and self-discovery set in a dream-like landscape filled with fairies.
 
After years of living in America, Clare Macleod and her father are returning to Ireland, where they'll inhabit the house Clare was born in -- a house built into a green hillside with a tree for a wall. For Clare, the house is not only full of memories of her mother, but also of a mysterious boy with raven-dark hair and dreamlike nights filled with stars and magic. Clare soon discovers that the boy is as real as the fairy-making magic, and that they're both in great danger from an ancient foe.
 
Fast-paced adventure and spellbinding prose combine to weave a tale of love and loyalty in this young adult fantasy.