The story is set during World War II and is about a family of Blitz refugees, Madge Arwell and her two children, Lily and Cyril, who have to relocate to Dorset, where they meet the Doctor.

As we return to Downton Abbey, the household is bustling with all the Christmas preparations. But, there's tension in the air between Sir Richard Carlisle, Lady Mary and Matthew... And, Bates' trial casts a dark cloud over the festivities. Will he be found guilty of the murder of his wife?