- 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
July 1917. As Isobel's plan to turn Downton into a hospital unites upstairs and downstairs in protest, O'Brien persuades Cora to make Thomas the hospital manager. Ethel enjoys the patients' attention whilst Edith earns respect as an auxiliary nurse. Chauffeur Branson, extolling the Russian Revolution, intends to be a conscientious objector but is rejected on medical grounds as former footman William, on his way to the trenches, proposes to Daisy. As Lang finds his trauma interferes with his work Anna discovers Bates working in a local pub. He tells her that Vera has been unfaithful and he is hopeful of a divorce. Violet and Rosamund learn that Carlisle coerced a reluctant Lavinia into exposing government secrets by using her father's debt - thus the engagement is still on.