By common consensus, there isn’t allowed to be more than one major movie a year that’s set at an archaeological site. Whether this is a shame, or whether one topsoil-and-shovels movie a year is already too many, is a question of principles. Leaping into the highest echelons of dig movies is The Dig, directed by Simon Stone with a screenplay by Moira Buffini. Typical period dramas pretend to offer history laid bare, with every layer of intervening time between our lives and the characters’ denuded away by movie magic. Here’s one that recognizes that historical reconstruction on film is itself a kind of archaeology; as with that down and dirty science we see in action here, the pleasure is in the digging. What’s found is for museums.

Ralph Fiennes plays the self-taught archaeologist Basil Brown, who hits upon the discovery of a millennium during an ostensible leisure project on a landed widow named Edith Pretty’s estate in pre-World War II rural Suffolk. Regional authorities want to file it under Viking and be done with the thing, but Brown insists that what he’s found is older, much older, and he’s right. (Fiennes’s dialect, part of a magisterial working class performance at every level from an actor we’re used to seeing play aristocrats, is a marvel throughout; he says “Voiking” and I cheer, it’s that simple.) Ms. Pretty (her real name, would I lie?), played with frayed nerves, poor health, warmth, and magnificent screen elegance by Carey Mulligan, gives Brown free reign over the site, even after the British Museum and its detachment of card-carrying scholars arrive to claim it. To them, Brown is no archaeologist but a mere “excavator.” The film’s portrayal of class is razor sharp. Much of its drama comes from the tensions between self-taught expertise on the one hand and prestige on the other. “I may not be a fellow at Cambridge,” Brown intones, cradling his pipe, “but I worked out what was down there.”

Exhuming the remains of forgotten worlds is not only the movie’s subject but also its method. Mike Eley’s cinematography fills the frame with clouds and wide skylines, then plunges us into the dirt itself, with Fiennes often seen caked in dust and, in one crucial scene, nearly buried alive. The work of pulling bodies and their worldly effects out of time’s annulling darkness is set against Europe on the brink of all out war; biplanes whiz over the site, reminders of death in life and life in death. There are moments of the movie that feel over-attached to its admittedly low stakes. Getting the site of an Anglo-Saxon burial ground catalogued before Europe goes to war doesn’t scream movie material. But when it gives its metaphors the space and scope to breathe is when this gem of a picture shines brightest.