The wedding approaches and excitement is in the air, but Branson's plans could rattle everyone. Spanish flu reaches the house and a desperate Thomas looks for a way to re-establish himself. Ethel faces a dilemma when the Bryants return with a heartbreaking proposition, and a decisive Anna forces Bates to think about their future.

Set at Christmas 1919 through New Years 1920, Downton Abbey is hosting a lavish Christmas party, yet despite being the season of goodwill, tensions are rife and Bates' arrest has cast a shadow over the festivities.