The movie 45 Years is unusual among movies because it focuses on a demographic seldom explored in the movies: the older married couple.

Kate (Charlotte Rampling) and Geoff (Tom Courtenay) have been married for 45 years. Kate’s a retired teacher who begins each morning by walking their German shepherd; Geoff, also retired, spends his days at their home in the English countryside. Kate’s the more social of the two, going out with friends and planning parties; Geoff, who is borderline antisocial, is perfectly happy at home reading books while avoiding a reunion with his old-time friends. The couple never had kids, and their home—where most of the action takes place—is neatly decorated in dark warm hues, reminiscent of a cottage. But they lack any pictures of themselves, causing Kate to probe Geoff why he—or she—had never taken any.

The movie begins on the Monday before Kate and Geoff’s 45th wedding anniversary party, which is on Saturday. That Monday, Geoff receives a package from Swiss authorities informing him that they have found the (possibly nearly perfectly preserved) corpse of Geoff’s former girlfriend, who had died tragically 50 years earlier in the Alps, during a vacation with Geoff. The reserved Geoff—from a generation when men didn’t typically speak about their emotions—surprisingly tells Kate of his life with this girlfriend. At first Kate listens with compassion, but soon her curiosity and insecurity get the better of her as she fears that Geoff married her as a replacement. She forces Geoff to go to the reunion with his friends, during which she goes up to the attic, snoops through Geoff’s old possessions and discovers an old picture that confirms that she is a near physical match for Geoff’s first love.

It’s a slow story that takes its time to unravel, despite the six-day timeline. The days are clearly separated: they begin with a black screen and a title that says “Monday,” “Tuesday” and so forth. Kate walks the dog; Geoff eats in the kitchen. Their house is spectacularly clean and cozy, and the movie’s photography of the English countryside—whether it’s Kate walking the dog in the fields or taking a boat ride in the old canal—is gorgeous. Although Kate spends the first five days putting the final touches on the anniversary party (she pays for the banquet hall and chooses music), their lives are slow but cozy. In one aspect, it’s a meditation of what life is like as we age and enter retirement. And even as Kate slowly discovers the truth about Geoff’s previous relationship—Geoff had purposely downplayed its seriousness—Kate’s journey is geriatric in pace.

Make no bones about it: Kate has an emotional transformation and, at their anniversary party, Kate clearly no longer sees her marriage or husband in the same light. But her transformation isn’t portrayed epically: there are no explosions, road trips or loud rows with Geoff (although they do have a gentle confrontation on Friday).

The mellow handling of Kate’s subsequent emotional burnout both makes for and distracts from the movie. It serves as an excellent metaphor for aging and our inability to process change in our later years. But it may let some viewers feeling disappointed that there is no definitive conclusion to Kate’s and Geoff’s emotions and thoughts. So, it feels less like a feature film and more like an episode of a TV show with the tension to be resolved on another day. But that’s exactly the purpose of the film: Kate, who’s been married for 45 years to a man she realizes she doesn’t know, has little prospects. She’s retired and in her 70s, so starting a new life may not be an option. And for Geoff it’s worse as he can’t fully articulate his emotional state. Anybody who watches 45 Years should realize that it is a meditation on aging, relationships, and happiness. It’s not a goal-oriented movie.