Christmas has come, and with it a sparkling white winterfrost. When Bettina's parents are called away unexpectedly, leaving her in charge of the house, the farm, and baby Pia, Bettina neglects to set out the traditional bowl of Christmas rice pudding for the tiny nisse. No one besides her grandfather ever believed the nisse were real, so what harm could there be in forgetting this silly custom? But when baby Pia disappears, the magic of the nisse makes itself known. To find her sister and set things right, Bettina must venture into the miniature world of these usually helpful, but sometimes mischievous, folk.