The Dig: Carey Mulligan and Ralph Fiennes shine, but then things get a bit muddy

This charming, beautifully made drama gets about halfway (maybe a little more, maybe 60 or 70 per cent) towards confirmation as a classic of English reserve before a stunningly uninteresting subplot concerning less charismatic characters arrives to deaden the closing scenes. There is still more than enough good work from Carey Mulligan and Ralph Fiennes to nudge The Dig up any list of Netflix recommendations.

Based on a novel by John Preston, Simon Stone's film deals with the discovery of a now-famous Anglo Saxon tomb in Sutton Hoo during the months before the second World War.

Mulligan plays Edith Pretty, widowed owner of the land. Fiennes is the dogged, self-taught archaeologist Basil Brown. Nicole Kidman, born only a few years before Fiennes, was once in negotiations, but, movies being what they are, we have ended up with an actor young enough to be the real Mrs Pretty's daughter. Oh, well.

Sexual tension

Like so many British films, The Dig has a great deal to do with class. The widow is from the upper-middle bracket. Mr Brown speaks with a Suffolk burr and is most at home in a battered cloth cap. The hints of sexual tension – rarely more than that – between lonely posh person and grunty man of the soil initially suggest a gender-swapped variation on the Ted and Ralph sketch from The Fast Show. (Don't worry. Monica Dolan is here to confirm that Mrs Basil potato isn't turnip dead.) But Mulligan and Fiennes are strong enough to shake off the unintended reminders.

We are more used to seeing Fiennes in the big house, but, born only a few miles from Sutton Hoo, the actor is utterly convincing as the humble bicycling antiquarian. His posture may be hunched. He may speak in respectful tones to those richer and more conventionally educated. But we are never left in doubt as to Brown’s pride in his profession.

The nobs from the British museum, summoned when he unearths a giant Anglo Saxon ship, are not going to shake him from his duties. Mulligan faces less of a transformation, but she is no less impressive as an ill woman struggling to make a connection before the curtain comes down.

Stone, an Australian directing his second feature, seems to have taken lessons from Terrence Malick’s Days of Heaven. Much of the script is delivered as internal monologue. Mike Eley’s spinning camera captures an idealised, dust-flaked England – Hurricanes and Spitfires manoeuvring above – as it worries through a famously glorious summer. Sometimes it takes a foreigner to capture a nation’s soul.

Dull romantic complications

It would be overstating the case to say the film falls apart in its last half hour, but focus too often strays to the dull romantic complications between a young couple drafted in to work on the later excavations. At first it seems that drab Lily James, wearing her specs like the beautiful secretary who will pull a transformation in the last reel, and Ben Chaplin, again a generation older than his romantic partner, are just there as background decoration.

It soon becomes clear, however, that we are actually supposed to care about his apparent impotence (or maybe homosexuality) and her romantic frustration (later wandering eye). This feels like a subplot from the novel – apparently told from various viewpoints – that should have been hastily plugged when it became apparent the chief stream was, with no assistance from tributaries, gushing so vigorously.

Chaplin and James aren’t bad. They are just stranded by a story that springs too jarringly from nowhere when our affections are already elsewhere invested.

None of which can sabotage the good work done by the two leads. With a little more weight behind the campaign, Fiennes and Mulligan could have been on the Oscar trail. As it stands, Mulligan will have to settle for the best actress nod she is sure to get for the imminent Promising Young Woman. She will have had worse years.

On Netflix from January 29th