"Jackaroo" is the story of Gwyn, the daughter of an innkeeper in a world resembling medieval England. In this society, many people are starving in the countryside as the Lords and Earls gather wealth for themselves. Though Gwyn herself is the daughter of a well-off household, she still has troubles of her own: the laziness of her brother, the question of who to marry. However, her own personal troubles are quickly set aside when thieves strike the area, carrying off an old couple's nanny goat and leaving them to starve for the winter.

Gwyn must forget these troubles as her father makes her and his servant, Burl, accompany two guests (a Lord and his son, who Gwyn thinks of as a "lordling") on a map-making trip in the North Kingdom. While on this trip, though, a blizzard strikes and Gwyn and the Lordling are left on...