Christmas Special (2012)
The episode begins a year after the end of the last series. The most important development is the revelation that Mary is eight months pregnant.
The whole family, including Mary, are heading to Scotland to visit their old friends and relatives Susan and Shrimpy and their rebellious daughter Rose.
During the visit it becomes apparent that Shrimpy and Susan no longer love each other; in fact Shrimpy admits as much to Robert, telling him that now they no longer have the distraction of raising Rose (now eighteen) they simply have nothing in common. This leads to him being extremely nasty to Susan, who in turn takes things out on Rose. To make matters worse Shrimpy is running short of money, just as Robert was before Matthew and Branson helped him to save Downton. By the end of the episode it has been decided that Susan and Shrimpy will go together to take up a government post in India, but Rose will come and live at Downton. All this makes Robert realize afresh how much he loves his wife and how lucky he was to have Matthew and Bates to help him save Downton.
There is love interest for Edith when her editor and suitor, Mr.Gregson, arrives in Scotland, and she invites him to join the houseparty. He makes a good impression on the family, especially Matthew, with whom he bonds over country pursuits. He tells Edith that he loves her and maybe now her family know him they will sympathize (we know from previous episodes that he has a wife in a lunatic asylum whom he cannot divorce). However, Matthew says that Edith cannot be involved in scandal, and he is going to tell Gregson that he must say goodbye forever at the end of the houseparty. This makes Edith realize that she has feelings for Gregson and she tells Matthew he cannot speak.
Mary overdoes things during the festivities, with the long train journey and dancing and so on. She and Anna head home early, and as soon as she arrives she goes into labor; Dr.Clarkson and Isobel look after her. Matthew comes straight home and is delighted to meet his son; there is now an heir to the Downton estates.
Whilst everyone else was away Isobel and Dr.Clarkson have spent a lot of time together, and he has begun to take quite a shine to her. He timidly questions her about marrying again, and she lets him down gently by pretending not to understand what he is aiming at.
In the servant's quarters, a new maid named Edna has taken a great fancy to Tom Branson (who has not travelled to Scotland and so spends a lot of time with his old friends amongst the servants). She becomes more and more forward until she completely oversteps the mark and Mrs.Hughes fires her. Mrs.Hughes tells Tom that he must behave in the way Sybil would expect of him; he breaks down and admits that he cannot cope without her.
Mrs.Patmore seems to have attracted a man, Mr.Tufton. He was very appreciative of her cooking and invited her to the local fair. However, Mrs.Hughes has seen him fondling and kissing other women at the fair and tells Mrs.Patmore. She realizes he was only interested in her skills as a cook and isn't too upset.
At the end of the episode we see Matthew driving back to Downton to celebrate the birth of his son. On the road he swerves to avoid an oncoming vehicle and his car overturns. The episode ends with a shot of Matthew lying dead under his car, and then cuts to Mary in hospital with her new baby son, unaware that she has just been widowed.