- Writers: Julian Fellowes
- Stars: Allen Leech , Brendan Coyle , Dan Stevens , David Robb , Elizabeth McGovern , Hugh Bonneville , Jim Carter , Joanne Froggatt , Kevin Doyle , Laura Carmichael , Lesley Nicol , Lily James , Maggie Smith , Michelle Dockery , Penelope Wilton , Phyllis Logan , Raquel Cassidy , Rob James-Collier , Siobhan Finneran , Sophie McShera
Spring 1920:- Mary and Matthew's wedding is fast approaching. O'Brien fixes for her nephew Alfred, a former hotel waiter, to be the new footman though Carson finds him inefficient whilst Daisy is annoyed that, in view of the amount of cooking she does, she is still a kitchen maid and has not been promoted. Anna finds a list of all Vera's contacts and tells John she intends to write to them to discover if any of them found her suicidal. Robert, meanwhile, finds the future of Downton Abbey at risk due to money problems but Matthew annoys Mary by refusing a legacy left him by Lavinia's father. Sybil and Tom Branson arrive from Ireland - paid for by Violet - but Tom's new situation causes some awkwardness,largely for himself and the officious Carson, though he is supported by the Crawleys. When Tom appears drunk and vocal at dinner, Edith's gentlemanly admirer Sir Anthony exposes snobbish guest Larry Grey as having drugged him and Matthew asks Tom to be his best man. Tom reciprocates by reconciling Mary and Matthew. Another guest, Cora's brash American mother, Martha Levinson, turns up and there is an inevitable clash with Violet over Old and New World values.