While Pullo descends into Erastes' netherworld, Vorenus negotiates a severance for veteran soldiers on behalf of Ceasar, who invites him and Niobe to one of Atia's parties. Cassius tries to convince Brutus that the life and death of the Republic is indeed in his hands.

Cora’s mother sweeps into Downton for Matthew and Mary’s wedding, but with the couple’s relationship under strain will they even make it to the altar? New footman Alfred strives to meet Carson’s high standards, under the watchful eye of his aunt O’Brien. Robert’s shocking news brings financial worries to the fore, on an unprecedented scale. Might he lose Downton itself and all it stands for?

Branson’s political views land him in hot water, and Sybil’s loyalty is tested to the limit. Ethel is torn between head and heart as she makes a difficult decision about her son’s future. Anna is dispirited at Bates’s silence, what could be the cause? Carson begins recruiting a footman, and good-looking candidate Jimmy sparks immediate interest below stairs.