Robert (Lord Grantham) learns that the bulk of the family's fortune has been lost due to his impetuous investment in the Grand Trunk Railway.
At Downton, Mrs Hughes finds out she may have breast cancer, which only some of the household hear about, causing concern, but the tumour turns out to be benign.
The family visits Violet's niece Susan, her husband "Shrimpie", the Marquess of Flintshire, and their daughter Rose, in Scotland, accompanied by Matthew and a very pregnant Mary.
At Downton, Edna Braithwaite, the new maid, enters Tom's room and kisses him; he asks her to leave and she is eventually dismissed.
Mary returns to Downton with Anna and gives birth to the new heir, but Matthew dies in a car crash while driving home from the hospital after seeing his newborn son.