Thirteen-year-old Claire Swift is intrigued by Aidan, an Irish boy who is new to her school. He has a secret which he eventually shares with her—at night, he cycles into another world, one which lies unsuspected on the fringe of their own. The Nightland is a beguiling, magical place, but for those who linger in it too long, it holds deadly danger. One night, Aidan fails to return from the Nightland. Now Claire, like Orpheus descending to the underworld to regain Eurydice, must try to get him back.