Charlotte Rampling and Tom Courtenay are in the form of their lives in this quietly heartbreaking drama.

Adapted by director Andrew Haigh from a short story by David Constantine, the film exposes the flaws beneath the tranquil surface of a long marriage with insight and compassion.

Oscar-nominated Rampling and Courtenay’s retired couple have been plodding among the lower slopes of old age at their home in the Norfolk Broads, amiably heading for the landmark of their 45th wedding anniversary, when an unexpected letter forces long-buried memories to the surface, revealing the unseen cracks in their relationship a week before their lavishly planned celebration. And, as the date draws nearer, jealousy, resentment and disappointment begin to stir.

Steering well clear of melodrama, Rampling and Courtenay brilliantly convey the roiling emotions and uncertainties of a couple who never expected to find themselves so close to the edge.