In the week leading up to her 45th wedding anniversary, Kate (Charlotte Rampling) is as busy as any hostess organising a party would be. Granted any Jewish hostess would be confused (hysterical) at the fact she has left confirming the function room, menu and buying her dress until a few days before. But smoked salmon starters and matching accessories are not an issue for Kate. She is far too cool, contained and English to sweat about the big stuff and even balks at her friend (Geraldine James) suggesting a make-up artist for the big night.

Life for Kate and husband Geoff (Tom Courtenay) is relaxed and they have the verbal shorthand of long-married couples who understand each other. No children, mind, but the film, which is adapted from David Constantine's short story In Another Country, doesn't shed any light on the reasons for that beyond Kate longing for the sort of framed photo montages families accumulate.

But then Geoff gets a letter. The body of Katya, his previous girlfriend who died in a walking accident in Switzerland 50 years before, has finally been found in a glacier. There is nothing to suggest foul play, but the authorities have him down as next of kin and want him to identify her body.

It all seems innocent enough and as Kate first puts it: "I can hardly be cross with something that happened before we existed, can I?"

But she is cross. Cross and hurt by Geoff's emotional remembrances of a woman she now learns he planned to marry. Studying his changes in behaviour, trips to the loft to look at slides of his lost love and the possibility of a trip to Switzerland weigh heavily on Kate, whose anxiety is conveyed brilliantly by Rampling. Why this veteran star doesn't get the gigs that are showered on Dames Helen and Kristin is a mystery as she is as good and often better.

Courtenay is also magnificent and their relationship is so real, it almost feels as though we are snooping on private moments. The brilliant writing and direction by Andrew Haigh is the reason for this. He has made a stirringly emotional film from the simplest of stories and knew exactly how to end it. Unusually for films these days, it was so good that 45 years did not feel long enough.