Lettie Peppercorn lives in a house on stilts near the wind-swept coast of Albion, with no one to talk to but Periwinkle the pigeon. Her days are filled with floor-sweeping, bed-making and soup-stirring. Her nights are filled with dreams of her mother, who vanished long ago. Nothing incredible has ever happened to Lettie, until one winter’s night. The night the Snow Merchant comes. He claims to be an alchemist - the greatest that ever lived - and in a mahogany suitcase, he carries his newest invention. It is an invention that will change Lettie’s life - and the world - forever.