With two daughters married and one to go, the Crawleys prepare for Edith to walk down the aisle with the rich, if somewhat aged, Sir Anthony Strallan. Edith can’t believe her good luck, since most of the young men in her cohort died in the war. Anthony appears to be similarly pleased, if a bit nervous.
As these happy preparations are underway, Mrs. Hughes waits anxiously to hear the lab report on her tumor. Suspecting that the secretive housekeeper is not well, Carson tricks Dr. Clarkson and Mrs. Patmore into revealing the seriousness of Mrs. Hughes’s illness.
In a case of tit for tat, Thomas gets even with his new enemy, O’Brien, for the incident of the purloined shirts from the previous episode. His revenge: he falsely tells Molesley that O’Brien is resigning, encouraging him to solicit her job for the daughter of a friend. When Molesley approaches Cora about the opening, she is shocked that O’Brien hasn’t told her. As a consequence, Cora and O’Brien are on the outs.
At the same time, the Crawleys are quietly planning to sell Downton Abbey, reduce the staff, and move to a smaller but still splendid ancestral house, which they visit on a picnic. This downsizing wouldn’t be necessary if Matthew would only keep his inheritance from Reggie Swire, the father of Matthew’s first fiancée, Lavinia. But Matthew is adamant about giving the fortune away and even refuses to read a posthumous letter from Reggie, certain that it will confirm what a cad he was in deceiving his dying bride-to-be.
At the village church, Edith and Sir Anthony are about to exchange vows when Sir Anthony makes a stunning announcement: “I can't do this! You know it's wrong!” He is referring to a meeting at which Robert implored him not to court Edith. She is, of course, devastated to be jilted at the altar. But Violet is immensely relieved: “Let him go, let him go. You know he’s right.”
Meanwhile, Mary has secretly read the letter from Reggie and discovers that he fully understood Matthew’s difficult position, thanks to a note he received from the dying Lavinia. Mary tells Matthew that his guilt is therefore misplaced and he has no reason to refuse the legacy. In the aftermath of the wedding debacle, Matthew tells Robert that he will invest the fortune in Downton Abbey, thus saving it.
In other events, Isobel and Ethel meet again. Anna interviews the confidante of the deceased Mrs. Bates. And Bates’s cellmate tries to frame him in concert with some guards.
Finally, Mrs. Hughes gets good new from Dr. Clarkson: “a benign something-or-other,” in the words of Mrs. Patmore.