Winston the mouse is on a Very Important Mission. On Christmas Eve, he finds a letter that has gotten lost on its way to Father Christmas. So, with no time to lose, he sets out to deliver it himself in time for Christmas Day! He has a lot of Very Exciting Adventures on his Very Important Mission and makes some wonderful friends along the way. Each chapter includes it's very own festive activity for all the family to enjoy together – including writing a letter to Father Christmas, making mince pies, designing your very own Christmas cards, making presents, creating decorations and so much more!