There’s a quality to the dialogue in“Downton Abbey: A New Era,”unlike anything usually encountered on film. People speak as if they want to be overheard — not by the servants, and not by the lords and ladies upstairs, but by an unseen audience sitting in a movie theater.

For our benefit and delight, they recount exposition and talk about other characters. They go out of their way to announce their feelings, albeit in a starched English way, and seem intent on telling us every last thing that screenwriterJulian Fellowesknows about them.

There’s a technical term for this kind of writing: “lousy.” Yet how lousy can it be if you’re enjoying it, at first with a touch of scorn, but gradually with genuine and increasing interest?

Perhaps the answer is that despite the milieu it depicts, “Downton Abbey: A New Era” is lowdown, lowbrow art. It’s not a brilliant adaptation of some classic novel, but rather a soap opera — the second film to spin off from the popular TV series. As a soap opera, it shows the seams of its construction and never hesitates to steer headlong into the obvious. But it also makes you wonder what will happen next, and keeps you absolutely planted in your seat until you find out.

In its first minutes, the movie sets two plot strains in motion. In the first, Violet (Maggie Smith), the family matriarch, has inherited a villa in the south of France, and her son Robert (Hugh Bonneville) and his gracious American wife, Cora (Elizabeth McGovern) — along with some other family members — make the trip to France to assume ownership.

The interesting part here is that the man who bequeathed the house was a French lover of Violet’s some 64 years earlier. Hmmm, what was the story behind that?

Michelle Dockery on the new ‘Downton Abbey’ film and the Obamas’ love for the British drama

Meanwhile, Downton Abbey is in need of repair. The roof is leaking. In fact — if you see the movie, notice this — it seems to be leakingeven when it isn’t raining.So that’s quite the leak. In order to get money for a roof job, the family decides to let a Hollywood studio shoot a movie on the premises. And so, a rush of technicians and craftsmen, not to mention a couple of big-name movie stars, converge on the Abbey.

Everything connected with the making of the movie-within-the-movie is fun — the awed reactions of the servants, the manners of the movie stars and the way the silent film director (Hugh Dancy) coaxes performances from his stars. But the South of France story develops nicely, as well, and the beauty of the location gives the film a boost.

The acting is splendid. Fellowes’ dialogue may not be subtle, but the actors are so familiar and at home in these roles that they make up for whatever is lacking. In a memorable scene, Bonneville as Robert has an explosion of emotion that’s moving and devastating, and McGovern embodies loveliness itself as Cora, a woman who somehow remains down-to-earth, despite having been waited on around the clock for the past 40 years.

But the standout here is Michelle Dockery as Lady Mary, whose husband is AWOL and who finds herself drawn to the movie people working in her home. Fellowes would like us to accept the notion that the upper classes, in this era, produced people of delicacy, restraint and probity. In scene after scene, as the sorrowful yet good-humored Lady Mary, Dockery makes us believe it.

M“Downton Abbey: A New Era”:戏剧。由休·博纳维尔主演,伊丽莎白McGovern and Michelle Dockery. Directed by Simon Curtis. (PG. 125 minutes.) In theaters starting Friday, May 20.