Beginning in the years leading up to World War I, the drama centers on the Crawley family and their servants.
Cast: Hugh Bonneville, Jessica Brown Findlay, Laura Carmichael, Brendan Coyle, Michelle Dockery, Joanne Froggatt, Thomas Howes, Rob James-Collier, Elizabeth McGovern, Maggie Smith, Dan Stevens, Allen Leech, David Robb, Jim Carter, Phyllis Logan, Siobhan Finneran, Sophie McShera, Lesley Nicol, Penelope Wilton, Maria Doyle Kennedy, Rose Leslie, Kevin Doyle
Mary endeavours to build bridges but Edith's secret continues to pose a threat, even after she thought there was nothing left to lose. As Henry settles into the role of husband and stepfather, the scars left by Charlie's death are slow to heal, and finding his place at Downton proves more difficult.
Romance blossoms but a betrayal of trust threatens the chance of lasting happiness. Thomas considers desperate measures.
The family face a shocking turn of events at Brooklands racetrack while Molesley and Daisy are put to the test.
Downton Abbey opens its doors to the public for charity, and tensions between Cora and Violet reach a dramatic climax.
Violet embroils the Minister of Health in the hospital row, but his visit ends in catastrophe. Mary's suspicions are aroused.
Anna and Mary face a crisis and a figure from the past surprises those above and below stairs.
Mr Carson and Mrs Hughes' wedding is fast approaching, but a misunderstanding threatens to derail the occasion, and when the big day arrives it also brings a few unexpected guests. Meanwhile, Edith reconnects with an old acquaintance, who comes to her aid in her hour of need, and over at the Dower House, Spratt has something to hide, meaning Denker is hot on his trail. Daisy jumps to conclusions over one of the countess's plots, and tensions mount over the hospital takeover, prompting Isobel to offend a friend.
What begins as a happy day out for the family and servants ends in panic and leaves Robert with a difficult decision to make.
Lady Mary's past catches up with her when an unwelcome visitor delivers an ultimatum, and news about the running of Downton Hospital puts Violet on the warpath.