45 Years, film review: Tom Courtenay and Charlotte Rampling paint an intense, slow-burning picture of marriage

Andrew Haigh's 45 Years stands as a rebuke to all those cosy recent comedies about the romantic escapades of mischievous OAP types. It is a very quiet film but one with a seismic kick. There is no Best Exotic Hotel-style jauntiness here. Instead, Haigh (who based the film on David Constantine's story In Another Country) shows that characters in their 70s can suffer just as acutely from jealousy, mistrust and existential angst as any star-crossed young lovers.

This is a study of a middle-class English couple who have been married for almost half a century. Kate and Geoff Mercer (Charlotte Rampling and Tom Courtenay) seem to live the good life. Their home is on the edge of the Norfolk Broads. The very first scene is of Kate walking her dog on a chilly morning. It is a blissfully pastoral scene. The birds are singing. The dog is barking. Kate herself is humming "Smoke gets in your Eyes," a song that has a special (albeit increasingly ironic) resonance for her and her husband. In a few days' time, they will be celebrating their 45th wedding anniversary with a party for their friends and family.

They seem entirely content with one another. Then, Geoff receives a letter written in German that summons up a figure from his past…and everything suddenly changes. The letter reveals that the body of Geoff's former girlfriend, who disappeared in an accident in the Swiss mountains in the early 1960s, has been discovered, perfectly preserved in the ice. "She has been there for 50 years, like something in the freezer, and now they've found her," Geoff mumbles over the breakfast table.

Haigh goes to great lengths to show the intimacy and familiarity between the husband and wife. He highlights banal details in their everyday life – Kate's shopping trips, Geoff's flailing efforts to fix a lavatory.

After so many years of marriage, they know everything about one another - or so it seems. Each is accustomed to the other's habits: the side of the bed they sleep on, how they deal with stress (in Geoff's case, by smoking), the books they start but never finish reading, their exasperation with a ukulele-playing friend.

45 Years has a deliberately low key quality. There are no melodramatic flourishes, no tantrums or furniture-throwing. During the most climactic moments, we can hear the clock ticking and the radio playing in the kitchen. This is a movie in which the slow click of a slide projector has a terrifying significance. Kate is slowly realising that there are aspects of her husband's personality she doesn't understand at all.

Geoff, meanwhile, is becoming more aloof and more distant as he contemplates the life he might have led had Katja not died. His old girlfriend doesn't just represent a road not taken. She reminds him of the youth and sense of purpose he has lost.

Rampling gives one of her strongest performances as Kate, the woman beginning to question all her long-held assumptions about her married life. "It is like she (Katja) has been standing in the corner of the room behind my back…and it has tainted everything," she remarks of the other woman who intrudes with such devastating effect on her relationship with Geoff from a distance of over 50 years.

Rampling's character is introspective and very quietly spoken but the actress still plays her with a frightening intensity. At first, she is tender and solicitous toward her husband but as she learns more about Geoff's relationship with Katja (in particular, the fact that he was her "next of kin") her attitude changes.

No-one does icy stares like Rampling or can convey so much distrust and disapproval in a simple frown. The role here is a companion piece of sorts to the one she played in thriller I Anna, in which she portrayed a woman of a similar age, desperately looking for romance.

Courtenay matches Rampling as the grizzled and distracted Geoff, who pays more attention to his lover from 50 years ago than to the wife he supposedly adores. Katja disappeared in 1962. That was the year in which Courtenay had his first big screen success in The Loneliness Of The Long Distance Runner. What torments Geoff the most is the idea that Katja looks the same as she did in 1962 while he is now a "decrepit" old man.There is an excruciating lovemaking scene at the start of which Courtenay is pictured in his y-fronts brushing his teeth.

This is a film about communication – or the lack of it. "You could have just told me, Geoff," Kate chides her husband. "I thought I had," is Geoff's plaintive reply.

He hasn't so much lied directly to her as neglected to tell her about feelings he once had for another woman. She tries to reason her way out of her own jealousy, saying she can hardly be "cross" about events that took place before she even met her husband.

45 Years is a slow-burning and deliberately enigmatic affair – and that is its strength. Haigh doesn't provide us with glib resolutions or explanations. Instead, at key moments, he will throw in close-ups of Rampling. It is up to us as an audience to read the emotions in her face and to decide whether we see resignation, forgiveness, tenderness, fury or a mixture of them all.

There are moments here which are brutal and despairing. At times, Haigh seems to be suggesting that even in a "happy" marriage, neither partner can ever really understand the other, and that at any moment their relationship can turn toxic. The film, though, is also open to a kinder, more optimistic reading. Good marriages are "full of history," as one Pooterish character tells Rampling.

It is precisely because they have endured so much already that the couple here have a chance of coping with revelations that might otherwise have shattered everything.