Disease, freezing temperatures, and the Revolutionary War bring bitter reality to the Reed home in December 1777. Captain Benjamin Reed is ordered to sail a supply shipment south to General George Washington. Days before Shenandoah's scheduled departure, Ben's first mate succumbs to smallpox.
Rebecca Reed had never feared the dreaded disease until her one-year-old daughter Felicity breaks out in the telltale rash. In the cold, dark days of Advent, Rebecca, Ben, and the Reed family wait in prayerful hope as Felicity fights for her life and they wonder who could be next.
With the rest of the family at risk, they decide to obtain the forbidden cowpox vaccine. Ben's brother Jonah, his uncle Isaiah, and Shenandoah's cook Adam Greene venture off in search of the outlawed vaccine. A blizzard hits. A tree crashes. Jonah crumbles to the ground. A woman with the face of an angel aids Jonah, but is it too late? And where are Adam and Isaiah?
As the death toll rises throughout the Colonies, the Reed family prays for more than one Christmas miracle.