Adele and her younger brother Axel grew up in a hamlet in the spectacular mountains of the Ardeche region in south-east France. Ten years later they have returned to their childhood home, and Adele now drives the school bus. Adele is desperate to keep the secret of her past - of when she was a boy. No one recognises her here now, but teenagers have a way of getting to the truth... When a terrifying snowstorm strands the bus on the mountain, Adele and her passengers take shelter in a cave, and that's when the stories come out.