Lugh's mother packed up and moved them from sunny Florida to tiny Steamboat Springs, Colorado after his father's accidental drowning. Resigned to his mom having to work a lot, and only just beginning to deal with his dad's death, Lugh is disappointed when she is called in to work on his fifteenth birthday.
After an unnerving dream, he decides to head to the nearby river where he ends up following a strange, urgent, internal pull. When another boy helps him rescue a young cat from the river, Lugh discovers a family secret he never suspected. Now, with his new cousin Abby and their friend Wyn, Lugh must figure out the rules of his new life before the forces that seek to destroy them can get the upper hand.