In this unique winter, Moomintroll chooses to remain awake rather than hibernate, eager to discover what the season holds. He soon finds that winter is nothing like he expected. Unusual creatures roam through the snowy landscape, and the Moominvalley is enveloped in the deep darkness of midwinter. Adding to the intrigue, an unusual visitor is about to arrive. Hemulen informs a bewildered Moomintroll that this visitor, known as Christmas, demands a lot of preparation.