Season synopsis
Contains spoilers for this season and earlier seasons.
Mary and Tom take more responsibility for Downton after Robert collapses with a burst ulcer. The local hospital’s merger with a larger institution also divides the family: Violet opposes it, while Cora supports the change and becomes hospital president. Carson marries Mrs Hughes, and Tom returns from Boston with Sybbie during their wedding celebration. Downstairs, Molesley’s examination results lead to a teaching job, while Thomas struggles with isolation and fears that the household no longer needs him.
Henry Talbot’s racing frightens Mary, particularly after his friend Charlie dies in a crash. She admits that she fears losing another husband as she lost Matthew, but eventually agrees to marry Henry. Edith becomes engaged to Bertie Pelham, who unexpectedly inherits the title of Marquess of Hexham. When Mary spitefully reveals that Marigold is Edith’s daughter, Bertie leaves because Edith had concealed the truth. Mary later helps reunite them, and Edith tells Bertie’s mother about Marigold herself before the wedding.
Thomas survives a suicide attempt after Baxter and Andy intervene, then finds work elsewhere. Carson’s worsening hand tremor eventually forces him to step back; the family arranges for Thomas to return as butler, with Carson retaining oversight. Henry and Tom open a car business, and Mary announces another pregnancy. Edith and Bertie marry on New Year’s Eve, while Anna gives birth to a son during the reception. Isobel and Lord Merton reunite despite his family’s interference, and his supposedly fatal illness proves to be a less dangerous form of anaemia. Violet and Cora reconcile as the family welcomes the new year.