Nina Landry is supposed to be taking her two children on a Christmas holiday. But the road from Sandling Island seems littered with obstacles. Most pressing of all, her 15-year-old daughter, Charlie, has yet to return from a night out.

Has Charlie run away? Or has something more sinister happened to her? As a series of half-buried secrets leads Nina from sickening suspicion to deadly certainty, the question becomes less whether she and her daughter will leave the island for Christmas - and more whether they'll ever leave it again.