And here's the jacket copy to go with it:
The faeries of the Oak are dying, and it’s up to a lone faery named Linden to find a way to restore their magic. Linden travels bravely into dangerous new territory, where she enlists the help of an unlikely friend—a human named Timothy. Soon they discover something much worse than the Oakenfolk’s loss of magic: a potent evil that threatens the fate of all faeries. In a fevered, desperate chase across the country, Timothy and Linden risk their lives to seek an ancient power before it’s too late to save everyone they love.
R. J. Anderson has artfully crafted a world of stunning magic, thrilling adventure, and delicate beauty, where a girl far from home must defeat the pervasive evil befalling her beloved faery realm.
The official publication date for Wayfarer is April 27, 2010.