Having inherited an English cottage from her mother's good friend, Dimity, American Lori Atherton (last seen in Aunt Dimity Digs In) is now settled into the village of Finch with her husband, Bill, their twin sons and her father-in-law. Shortly before Christmas, Lori's idyllic holiday plans are shattered when a derelict collapses in their snowy driveway. While the nameless man lies comatose in a local hospital, the late Dimity, who communicates from the other side by writing in a special journal, encourages Lori to pursue the man's identity.

Bill is suddenly called to Boston for a funeral, so Lori teams up with the kindly Father Julian, a Catholic priest who runs a local homeless shelter, and who knows the man but not his real name or background. The mystery unwinds as Lori and Father Julian trace the trail of the charismatic stranger, who seems to have touched so many people in a positive way. As the duo discover the nameless man's fascination for WWII airfields, and uncover his family history, they and the other villagers experience a Christmas like no other.