The club is forced to make an uneasy alliance with unforeseen consequences.
Robert and Carson are dismayed when a Labour government comes to power in the general election of 1924; Lady Mary receives another proposal from Tony Gillingham.
Wedding dress drama takes a turn for the worse; hospital debate escalates; a volunteer helps Edith.
Henry Talbot invites the Crawleys to watch him motor racing at Brooklands; Violet makes a plan which surprises the family and delights Denker; Mr. Molesley and Daisy must rise to the challenge on examination day; Andy's secret is brought to light.
Mary's past catches up with her when an unwelcome visitor delivers an ultimatum, and news about the running of Downton Hospital sets Violet on the warpath.