Starring Charlotte Rampling and Tom Courtenay. Rated PG.

Two old acting hands show us how it’s done in an exquisite chamber piece that examines the ephemeral nature of security and the past. Writer-director Andrew Haigh has just the right touch to adapt David Constantine’s slight short story into a smart vehicle for U.K. stars Charlotte Rampling and Tom Courtenay. These former faces of the Swinging ’60s play Kate and Geoff Mercer, planning their 45th wedding anniversary (they missed their 40th because of his heart surgery) for that very weekend, when a letter from Switzerland arrives.

The body of his long-missing first love has been found in an Alpine glacier. Unlike Geoff and Kate, the hauntingly named Katya’s been perfectly preserved. Suddenly, he’s out in the garden, smoking cigarettes again. And now he’s spending too much time in the attic.

45 Years is full of tiny background details that may feel random but subtly comment on the central action, set in Norfolk, England’s most easterly point. When Kate goes for a boat ride on one of the canals carving up the area’s “broads”, a recorded voice says, “If the Romans had dug somewhere else, these broads probably wouldn’t be here today.” Certainly, Kate wonders if she’d be here now if Katya hadn’t died. But the movie’s not just about boats not taken; there’s all the vitality and potential that slips away over time. Will Geoff get it together by Saturday? Does it really matter?

By the way, these are people who listen to Mozart at home. And one of the most profound moments has Kate digging out some old sheet music for her piano, only to put it aside to play some dark Sibelius from memory. So, in my only niggle, I wonder if they would really choose the most obviously nostalgic pop tunes for their party—especially those with such pointed lyrics as “Young Girl”, “Smoke Gets in Your Eyes”, “Go Now”, and, of course, “Happy Together”.