After going to a funfair the night before, Leila wakes up in an empty city. Where are her parents? Where has everyone gone? Thinking she must be the sole survivor of an unthinkable catastrophe, she wanders the weirdly deserted streets. Until she meets four other mystified strangers. Together they hole up at a plush hotel, and set out to understand what has happened, why they are surrounded by gigantic boiling clouds and what these apocalyptic events actually mean.