Dusty Carrick lived in the small town of Skene Falls, Oregon, her entire life. And, like many of the local children, she played with "imaginary" Pixie friends in Ten Acre Woods. But the Pixies are not imaginary at all, and Ten Acre Woods is their home. Now, the woods are in danger, and if it falls, the Pixies too will die. Only Thistle Down, exiled from her tribe and trapped inside a mortal woman's body, can save her people-as long as she can convince Dusty to help her before it's too late.