It's 1927 and life at Downton Abbey still continues, but things are turned upside down with the announcement that King George V and Queen Mary are planning to visit the estate!
The staff are thrilled with the prospect of a royal visit, until the King's Butler and the Royal Household arrive, bluntly informing the staff that they will not be needed during Their Majesties' visit. The staff isn't going to take this lying down. Meanwhile, Lady Mary is feeling the pressure of running the estate and Branson might have a second chance at love.
Almost the whole cast of the series returns with the exception of Lily James's Lady Rose. One new Crawley is introduced: Robert's cousin Lady Maud (Imelda Staunton), a widow who has been semi-estranged from the rest of the family for many years but is returning to Downton in her capacity as lady-in-waiting to the queen. Tuppence Middleton plays Lucy, Lady Maud's maid and companion.
Tropes present in the film:
- Big Fancy House: Not just the eponymous abbey, but the end of the film takes place at Harewood House, home to the Earl of Harewood (Princess Mary's husband in 1927) and the Lascelles family.
- Beware the Nice Ones: Mary asks Carson to return. He does return and the look on his face when he catches sight of the King's butler is one to be frightened of. This is his domain, no-one else's.
- Child of Forbidden Love: It turns out that Lady Maud's maid Lucy is in fact her daughter. Lady Maud, already several years a widow, had a long-term affair with one of her servants and Lucy was the result.
- Demoted to Extra: Over a two-hour movie just about every character has some business and story beats, except for Mr. Bates, who does pretty much nothing over the film.
- The Disease That Shall Not Be Named: Near the end Lady Violet takes Lady Mary into a side room and tells her a secret: Violet doesn't have long to live. It's obviously cancer but the C word is not used.
- Dude, Where's My Respect?: A big point of contention with the Downton Staff and the Royal Household. Traditionally visiting servants take orders and work in tandem with the host servants, but the King's Butler insists the Royal Household run the household and wait on Their Majesties, while the Downton staff ... stand and around and do nothing. The Downton Staff are not going to take this sitting down.
- Fanservice: A couple of extended scenes with Lady Edith in nothing but a tight slip, as everyone fusses on getting her a dress that fits for the royal ball.
- Flat "What": Mary's reaction when Robert announces the King and Queen are coming to visit Downton.
- French Jerk: All the king's servants are horribly obnoxious, including the haughty French cook Monsieur Courbet, who insults Mrs. Patmore and denigrates the Downton kitchen as well.
- Green-Eyed Monster: Andy the footman has this in a big way when the handsome boiler repairman comes to Downton and makes eyes at Daisy, and she seems receptive.
- Hate Sink: Mr. Wilson, The King's Page of the Backstairs, is a condescending micromanaging asshole. While the King's visitation is causing all sorts of stress for the family and staff, he's not an antagonistic character so Mr. Wilson picks up the slack by giving the audience someone to root against. While the King's staff isn't necessarily pleasant to begin with, Monsieur Courbet is given a lot of comedic scenes, the royal housekeeper isn't as prominent, the Footmen largely keep to themselves, and Richard Ellis, the Valet, is much easier to get along with. Mr. Wilson is also the only major conflict character to be treated unsympathetically as Lady Maud and the Dowager's conflict ends amicably, Thomas is a firmly heroic, if sour, character, and even the Seamstress's thieving is given a small degree of sympathy.
- Historical Domain Character: King George V, his wife Queen Mary, their daughter Princess Mary, and her husband Viscount Lascelles (later the Earl of Harewood). One subplot involves Princess Mary's marriage, which is deeply unhappy.
- Insistent Terminology: Lady Violet does not like to be told she is arguing.Robert: There's no need to argue.
Violet: I never argue. I explain!
- The king's jerkass butler gets very angry when he's called a butler, insisting that he is "The King's Page of the Backstairs." (He's the king's butler.)
- King Incognito: Accidentally. Tom Branson, walking on the Downton grounds, spots a well-dressed woman quietly weeping on a bench. Taking her for a commoner, he sits next to her and they chat for a while, and Tom says some kindly words. What Tom doesn't know is that the lady on the bench is Princess Mary, the king's daughter; Tom's pep talk leads her to demand that her husband make some changes and stop being such a dick.
- Leaning on the Fourth Wall: Earl and Countess Grantham indulge in this with their last lines of dialogue in the last scene.Cora: I do enjoy our adventures.
Robert: But isn't it fun when they're over?
- Mandatory Un Retirement: Lady Mary feels she can't cope with the pressure of a Royal Visit, and doesn't trust Thomas, and asks Carson to come back as butler. He happily obliges.
- Maybe Ever After: Thomas finally gets a boyfriend—maybe! It's Ellis, the king's valet, who uses his position to get Thomas sprung from jail after the gay club where Thomas was dancing is raided. They have a kiss goodbye, Ellis gives Thomas a locket as a keepsake, and the possibility that they will see each other again in the future is dangled.
- Remember the New Guy?: Robert's cousin Lady Maud, lady-in-waiting to the Queen, never mentioned throughout the course of the show but popping up in this movie. Justified In-Universe as Maud having kept her distance from the rest of the Crawleys for many years (and further justified when Maud's secret is revealed). There's also the fact that, as she's female, she has no claim to Downton anyway...
- Reset Button: At the end of the series, Carson had a tremor that led to his retirement, and Molesley the Butt-Monkey had left service and found dignity as a schoolteacher. In the movie, plot machinations lead to Carson coming back to be head butler again (with his tremor having mysteriously disappeared) and Molesley pinch-hitting as a footman again (and being the Butt-Monkey as usual).
- Romancing the Widow: Gender-flipped. Tom Branson, seven years a widower, falls in love with Lucy, Maud's maid. They're dancing together in the last scene.
- Serious Business: As usual at Downton, people are getting spun up into a lather over the most trivial stuff. In this instance it is all-out war between the Downton staff and the King's own servants as to who will get to serve the royal family dinner.
- Slipping a Mickey: How M. Corbet the king's cook is dispatched, allowing Mrs. Patmore to cook for the royal family. Mrs. Bates slips him a "sleeping draught" in his tea.
- Society Marches On: Robert jests at Edith and Herbert visiting Downton without bringing any of their own servants, not even a nanny with them.Herbert: It's 1927, we're modern folk!
- Token Good Teammate: The King's staff are for the most part, very controlling haughty people save for the King's Valet Richard Ellis. Ellis's scenes with the Bates's and Thomas establish him as a casual and friendly man he even helps the Downton Staff sabotage the Royal Staff and later uses his status as a member of the King's household to get Thomas out of being arrested.
- Tyrant Takes the Helm: The staff goes head to head against the King's Butler and the rest of the Royal Household when they take over the preparations for Their Majesties' visit. Mary described as "terribly scary" which is intercut with the Butler saying to "stay out of my way" to a furious Mrs. Hughes and Mrs. Patmore doesn't think highly of the Royal Cook either. Some characters are even heard considering pushing back to preserve the Abbey's honor, even though disregarding the authority of King's servant could easily cross into treason, in Carson's eyes anyway.
- Where Everybody Knows Your Flame: Thomas, temporarily relieved of duty, goes to have fun in nearby York and finds himself in a gay nightclub (it's northern England in 1927 so the nightclub is hidden in a warehouse).