Gaia's younger sister Esme is supposed to be flying back to England with her family after the party, but she can't leave with Gaia missing--especially because nobody remembers Gaia leaving the party. Or if they do, they're not saying. Everyone at the lodge has their own secrets: the little rich girl, the ex-boyfriend, 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 her. The clock is ticking, and it's down to Esme to piece the clues together and work out who--if anybody--is telling the truth.