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?
The estate's future is hanging in the balance and Mary is hoping to receive a bailout from grandmother Martha. Violet also attempts to help her make sure that Downton puts on a bigger show than ever before with a grand party for friends and neighbours. Mrs Hughes gets some news that worries her. O'Brien's attempts to boost Alfred's progress are met with disapproval from Thomas.
Edith's wedding day arrives but will her enthusiasm be able to convince the family that Strallan's age doesn't really matter. Mrs Hughes awaits her results. Anna manages to make a breakthrough as she tries to help Bates. Mary decides to take matters into her own hands to secure the estate's future.
Branson's political views manage to get him into trouble while Sybil's loyalty is tested to the limit. Ethel finds herself being torn between head and heart as she makes a decision about her son's future. Anna is upset by Bates's silence and wonders what could be the cause. Carson looks for a new footman and a good-looking candidate called Jimmy creates interest below stairs.
An exciting offer for Edith divides opinion in the house. Isobel ends up throwing Ethel a lifeline. Ivy is attracting plenty of attention below stairs. Anna’s perseverance finally pays off for her.
Tempers are left on edge after a kind gesture by Isobel backfires. Mary attempts to fight Branson's corner after his decisions are put under scrutiny. Robert and Cora's relationship feels the strain and Violet attempts to make them see things differently. Some extreme measures are taken by Bates.
It's a good day as Anna's patience is rewarded and Edith gets some admiration from an unexpected quarter. Matthew refuses to back down over the estate management. Branson's plan for the christening causes some consternation, as does the sudden arrival of his brother.
There's excitement in the house and village as the annual cricket match approaches, and the event brings out Robert's competitive side. Violet's great-niece Rose shows up but a trip to London reveals there is more to her than meets the eye. Matthew and Mary look like they are keeping secrets from each other. Thomas finds out that his future lies in Carson's hands.