It’s an often-cited and inarguable truth: There are few meaty roles in Hollywood for women past a certain age. If your hair has started to turn gray, you may be cast as the concerned mother or nagging wife. If you’ve long been eligible for the senior citizen discount at Denny’s, your options narrow even further—study Betty White, lady, because it’s the inappropriate grandma or zilch.

In Andrew Haigh’s 45 Years and Nicholas Hytner’s The Lady in the Van, however, two titan elders of stage and cinema, Charlotte Rampling and Maggie Smith, are accorded the spotlight. Rampling, incredibly, is in a romance. And Smith—well, her character lands squarely in the wacky old bat category, but there are shades of genuine humanity, at least.

Rampling’s been nominated for an Academy Award for her understated turn as Kate, a woman contentedly living a peaceful, child-free life in the country with her husband, Geoff (Tom Courtenay). They talk about literature and trips into town, and are also planning a party for their 45th wedding anniversary because Geoff had been sick for the 40th.

But then Geoff gets a letter. “They found her,” he says aloud, without giving viewers a clue about who this person is. “My Katya.” Oh.

From this early moment on, the couple’s idyll inchingly dissolves. Katya was Geoff’s girlfriend, but more than that: She was listed as his next-of-kin, he later reveals. Kate’s confused and presses: They’d pretended they were married so they could travel together without scandal. Kate knew that Geoff had had a lover who’d died while they were hiking through the Alps. The rest, though, he never told her.

Kate, still a stylish beauty, tries to be magnanimous—after all, this happened before she and Geoff met—but can’t quite get past how the news seems to rattle and distract him. One night, for example, he rises to go to the attic. Later Kate does the same, hunting for things she doesn’t really want to find. (Even their dog barks a warning, as if he’d seen a ghost.)

Adapted by Haigh from a short story, 45 Years is a taut, extremely low-boiling portrait of marital strife, one unusual in light of the ramifications that an incident from five decades ago has on a happy union of nearly as long. The film is all increments—of both actions and expressions—to be read into, such as the couple’s failed attempt to have sex (but note what happens just before it’s cut short).

Then there’s Rampling’s masterful performance, her expressions and tone changing so subtly throughout the film that her increasing jealousy, doubt, and resentment might be missed. At one point, she lends the hint of a hiss when Kate tells Geoff, “Please stop saying her name!” You believe that this seasoned woman comes to have the self-doubt of a teenager, quietly beside herself as she asks Geoff difficult questions in otherwise tranquil moments. Kate’s mood swings at their party are gutting, not only because you feel her pain but because it’s likely no one else there has noticed the sorrow between her smiles.

Courtenay holds his own, playing Geoff as a wholly unique character who at once speaks haltingly, like an old man whose mind is slipping, yet still reads Kierkegaard, recalls and muses on dusty memories, and isn’t too tired for an impromptu living-room dance with his wife. (The film’s 1960s soundtrack is terrific, by turns sad and fun.) And, apparently, he’s a man vulnerable to thoughts of a lost love. The message that Katya’s body has been found is, for both Kate and Geoff, initially a tiny crack. But it doesn’t take long before it breaks into a chasm.

45 Years opens Friday at Landmark’s Bethesda Row and E Street cinemas.