45 Years begins the way many tense mysteries do—with a dark secret being unearthed. But this is no Nordic crime thriller, or horror film about monsters emerging from the deep. The cold case that’s reopened in 45 Years is a romance, involving a long-ago love of Geoff’s (Tom Courtenay) who died in a hiking accident decades ago. The news that her body has finally been found begins Andrew Haigh’s quietly taut drama, and slowly infects Geoff’s marriage to Kate (Charlotte Rampling) just as they prepare to celebrate their 45th anniversary.

If this sounds like it could be tough going, it is. But 45 Years is methodical in its devastation, chronicling a busier-than-usual week in Kate and Geoff’s quiet, settled life in Norfolk, England, after this dark news breaks. Like Haigh’s last film, the masterful 2011 romantic drama Weekend, it succeeds most with its muted moments, in the stilted pauses and loaded glances Kate can’t avoid as Geoff’s memories begin to take over every part of his life. Haigh brilliantly sidesteps melodrama and clunky exposition as he picks at the margins of this seemingly stable relationship.

His biggest weapon, of course, is Rampling, who manages to convey so much without speaking. It’s perhaps awkward to praise Rampling, who deservingly received an Oscar nomination for her performance, so soon after she aired a host of opinions about “racism against white people” in a French radio interview, but her work in 45 Years is undeniable, a testament to an incredible career of understated performances. Kate is a woman who exudes contentment and confidence in her life: She and Geoff don’t have children and are less sociable than some of their friends, but that’s easily explained by their strong connection.

Haigh, who also worked on the HBO show Looking, builds up the world around Geoff and Kate with similar grace. Weekend, centered around the gay scene in the mid-sized English city of Nottingham, had an amazing sense of place for a film that was largely set in people’s apartments. Geoff and Kate’s countryside existence in Norfolk feels parochial in all the right ways—comforting and picturesque—until Kate begins to chafe at Geoff’s obsessive focus on the past, at which point the walls start closing in. The couple’s friends go from supportive to pesky, and Kate suddenly can’t walk down the street without being reminded of her husband’s old flame. Haigh shifts the world on its axis in a thousand subtle ways, without needing to lean much on dialogue.

45 Years is based on a short story, “In Another Country” by David Constantine, who was in turn inspired by a real news story of a glacier melting enough to reveal the perfectly preserved corpse of someone who’d died on a French mountain decades before. It’s an apt and disturbing metaphor for the kinds of hidden secrets that can surface only decades after the fact. Geoff hasn’t so much lied to Kate about the past as he’s buried it himself, so long resigned to the loss of the alternate life he could have led. Kate’s inadequacy isn’t in trying to compete with another person for her husband’s affections, but in trying to have the life she’s led measure up to another that exists only in fantasy. It’s a horrifying scenario to consider, but at the same time, a disturbingly plausible one.

Eventually, the film’s plot ramps up to mete out more crushing revelations, including a scene with a slide projector that Haigh strangely foreshadows in the opening credits of the film. But just as it seems 45 Years is building to an unnatural, histrionic conclusion, Haigh and Rampling pull back again and, with one wordless closing shot, deliver the biggest blow of all—one that’s worth the 95-minute running time alone, and that lingers long after the lights go up.