Gaia Gill was last seen at a house party on Bluff Point, Moon Mountain Resort, New Hampshire, in the early hours of Sunday morning. Her family is very concerned about her and is seeking any information on her whereabouts. Gaia Gill is missing. Gaia is beautiful and smart and has everything to look forward to. But on the night of her going-away party at the winter resort she'd been working at, she disappears without a trace. Her younger sister, Esme, is supposed to be flying back to England with her family after their vacation with Gaia. But how can they leave when Gaia is gone? Especially because nobody remembers Gaia leaving the party. Or if they do, they're not saying. Everyone has their own secrets: the little rich girl, the exboyfriend, the ski instructor, the failed reality star. Esme's out of her depth searching the dark, dangerous forests and icy slopes of Moon Mountain, until she teams up with a local boy who promises to help. But the clock is ticking. The longer Gaia is missing, the less likely it is she'll make it back ... alive. And it's up to Esme to piece together the clues of her final hours before it's too late.