September 1916. Matthew, on military leave, returns to Downton. He announces his engagement to Lavinia Swire. Mary pretends to be happy for them but is in love with Matthew. Meanwhile, she has invited Sir Richard Carlisle, a powerful and wealthy newspaper mogul, to visit Downton. The servants prepare for a concert to help fund the local hospital. Bates tells Anna that he is finally able to get a divorce and proposes. Bates' estranged wife Vera arrives at Downton and demands that Bates resign and
April 1917. Robert informs Mrs Patmore that her soldier nephew was executed for cowardice. Thomas goes to work under Dr Clarkson at the village hospital along with Lady Sybil. Downton becomes a war-time convalescent home. Matthew is unhappy about returning to England for a recruitment drive. Lavinia is confronted by Richard, an old and unwelcome family acquaintance. Edith volunteers to drive a tractor to help farmers during the war. At the Drake farm, Edith and Mr Drake are mutually attracted. W
July 1917. Violet objects to Downton becoming a war-time convalescent home, while Isobel takes charge. Cora gets Thomas, now an Acting Sergeant, assigned to oversee Downton's military convalescents. Violet, believing that Mary and Matthew are still in love, schemes with Lady Rosamund to end Matthew's engagement to Lavinia. Violet believes there is more to Lavinia's relationship with Richard than as a family friend. William proposes to Daisy before going to war. Daisy does not love William, but M
March 1918. New housemaid Ethel continually flirts with Major Bryant. Mrs Hughes discovers them in bed together and dismisses Ethel. A few months later, Ethel returns, announcing that she is pregnant with Bryant's child. Preparations are under way for a concert at Downton. Tensions flare between Isobel and Cora, while Edith learns that Matthew and William have gone missing at the war front. Branson asks Sybil to run away with him, but she is reluctant. Robert visits Bates at a nearby pub where h
August 1918. Matthew has suffered a serious spinal injury and is paralysed from the waist down, leaving him unlikely to ever father children. He wants Lavinia to forget him and ends their engagement, while Mary attempts to nurse him back to health. Mrs Hughes secretly helps Ethel and her baby after Bryant refuses to have contact with them. Having shielded Matthew from an explosion, William returns to Downton with terminal injuries. He wants to wed Daisy before dying. Mrs Patmore persuades a relu
November 1918. A severely burnt and disfigured Canadian officer arrives at Downton and declares he is the assumed dead heir, Patrick Crawley. Mary rejects the claim, but Edith is persuaded as he recounts memories of their childhood at Downton. Robert's solicitor, Murray, investigates and learns that Patrick Crawley had a close friend who emigrated to Canada. Violet presumes he is impersonating Patrick to claim the family fortune. After Edith vows to never stop trying to prove he is Patrick, he a
Early February 1919. Matthew begins feeling sensation in his legs. He announces that he and Lavinia will marry soon. Violet tells him that Mary still loves him, but Matthew feels obligated to marry Lavinia. Richard distresses Anna by asking her to spy on Mary; this leads Carson to reject his employment offer in Richard and Mary's new home. Bates realises Vera committed suicide to frame him for murder. Mrs Hughes contrives a meeting between the late Major Bryant's parents and Ethel and her baby.
April 1919. The family are appalled that Sybil wants to marry Branson, a chauffeur. As preparations are under way for Matthew and Lavinia's wedding, Cora, Carson and Lavinia fall ill with Spanish flu. Despite being in love, Matthew and Mary acknowledge they can never marry as it would be cruel to Lavinia. Lavinia overhears their conversation and later tells Matthew she will not prevent his happiness. Ethel refuses the Bryants' offer of money in exchange for custody of their grandson, Charlie. Ja