Every year, Margot spends the Christmas holidays with her grandparents at their house, nestled deep in a valley in the snowy mountains. With presents to wrap and biscuits to make, Granny and Grandad are always so busy! This year, Margot is busy too. Granny and Grandad have asked her to look after an injured foal, Marshmallow. As Margot gets to know Marshmallow, she soon realizes that there’s something special about the little foal.