After the death of their father, 15-year-old Mairi and her younger brother Jamie are forced to spend the summer with their estranged grandfather in the rural mountains of Northern California. Expecting to be miserable, Mairi is instead drawn into a world of magic straight out of the Celtic fairy tales from her childhood. Facing faerie curses and vengeful druids, a trip back in time to ancient Scotland threatens to become even more dangerous than anticipated...