Season synopsis
Contains spoilers for this season and earlier seasons.
Mary and Matthew begin married life at Downton in 1920. Tom and Sybil return from Ireland to attend the wedding, and Matthew chooses Tom as his best man. Robert’s celebration is clouded by the loss of much of Cora’s fortune through a failed railway investment. Matthew reluctantly agrees to accept money left by Lavinia’s father as an investment in the estate, giving him a say alongside Robert. Edith’s engagement to Sir Anthony Strallan ends at the altar when he calls off the wedding. Only afterward, when Tom is implicated in an arson attack in Ireland, he escapes to Downton without Sybil; she arrives safely soon after.
Tom and the pregnant Sybil settle back at Downton, where family tensions surround their marriage and his place in the household. During childbirth, Robert follows obstetrician Sir Philip Tapsell’s reassurance over Dr Clarkson’s warning that Sybil may be suffering from eclampsia and needs hospital care. Sybil gives birth to a daughter but dies after convulsions that night. Tom is left grieving and uncertain of his future, while Cora blames Robert for dismissing Clarkson’s concern. Bates is eventually released from prison after Anna finds evidence that helps clear him of Vera’s murder, and Violet later encourages Tom to manage the estate.
After the summer cricket match, Mary and Matthew learn that each had separately consulted a London doctor about their childlessness; Mary reveals that she has had a minor operation, giving them hope of a family. By the next summer, Mary is pregnant and travels with the Crawleys to Scotland. She returns early to give birth to a healthy son, George. Matthew reaches the hospital, meets his newborn heir, and drives back to Downton with the news. His car crashes on the way, killing him and leaving Mary widowed.