Takes place in mid 1918. Lord Grantham receives some shocking news from the front. Both Matthew and William have been wounded in France. Unfortunately, William has sustained serious damage to his lungs and is unable to recover, prompting him to ask Daisy to marry him before he dies. Meanwhile, Matthew suffered a serious spinal cord injury and is paralyzed from the waist down, never to walk again or father children. Lavinia insists that this changes nothing and that she is not concerned about having a sexual relationship and children, and only wants to care for him, however Matthew tells her to leave and forget him, while Mary attempts to nurse him back to health.
A new maid, Jane, is hired after Carson and Mrs Hughes decide to take her on despite being a war widow with a child. Mrs Hughes has also been secretly helping Ethel and her son, Charlie, as her lover Major Bryant has ignored her pleas to see the baby.
Despite not truly loving William, Daisy is pushed into marrying him by Mrs Patmore, who wants William to die happy, and by William's wishes that Daisy is left with a widow's pension so that she can be looked after. They marry while William is bed-ridden, surrounded by the other staff, Edith and the Dowager Countess. William dies in his sleep, not long after, with Daisy by his side.
Bates is taken aback when Vera threatens to expose old secrets about Mary and the circumstances of Pamuk's death. When Mary discovers this, she confesses everything to Richard Carlisle and asks him to help. While he accepts, he does so expecting her to marry him, as she is now in his debt, even going so far as to announce their engagement in the newspaper without informing her, leaving Mary in a difficult position. Carlisle tricks Vera into signing a contract, preventing her from selling the story to anyone else, but on finding out, she warns that she will still bring ruin to Bates.