Laura ventures into the nearby town of Milford once a week for shopping and to the cinema for a matinée. Returning home from one of her weekly excursions, at the station she gets a piece of grit in her eye which is removed by another passenger, a doctor called Alec Harvey (Howard). Both are in early middle-age, married, and both have two children. The doctor is a general practitioner who also works one day a week as a consultant at the local hospital, but his passion is for preventive medicine, such as addressing the causes of respiratory illness in miners.
Enjoying each another's company, the two arrange to meet again. They are soon troubled to find their innocent and casual relationship quickly developing into love.
For a while, they meet furtively, constantly fearing chance meetings with friends. After several meetings, they go to a room belonging to a friend (Valentine Dyall) of the doctor, but they are interrupted by the friend's unexpected return. This brings home the fact that a future together is impossible and, wishing not to hurt their families, they agree to part. Besides, the doctor is soon to leave for Johannesburg, South Africa.
Their final meeting is at the railway station refreshment room which we see for the second time with the poignant perspective of their story. As they await a sad and final parting, Dolly Messiter, a talkative friend of Laura, invites herself to join them and is soon chattering away, totally oblivious to the couple's inner misery.
As they realise that they have been robbed of the chance for a final goodbye, Alec's train arrives. With Dolly still chattering, Alec departs with a last look at Laura but without the passionate farewell for which they both long. After shaking Messiter's hand, he lightly squeezes Laura on the shoulder and leaves. Laura waits for a moment, anxiously hoping that Alec will walk back into the refreshment room; he does not. As the train is heard pulling away, Laura suddenly dashes out onto the platform. The lights of a passing express train flash across her face as she conquers her impulse to commit suicide; she then returns home to her family.
In the final scene of the film, which does not appear in the original Coward play, Laura's husband Fred suddenly shows that he has not been completely oblivious to her distress in the past weeks, and saying "Thank you for coming back to me" takes her in his arms.
The film neither mentions the Second World War nor any of the hardships that it brings. While no character refers to a specific time, the fictional film within a film Laura and Alec see Flames of Passion, which is newly released, displays a copyright date of 1938. When Laura returns home following the first (and last) scene, her daughter wishes to see a pantomime, suggesting a setting in time during the weeks before Christmas. A further indication the film takes place in winter is that one scene appears to be set at night except that people greet each other with "good afternoon".
As is normal in films based on stage plays, the film depicts places that are only referred to in the play: Dr. Lynn's flat, Laura's home, a cinema, a restaurant and a branch of Boots the Chemists. Additionally, a number of scenes have been added which are not in the play: a scene on a lake in a rowing boat where Dr. Harvey gets his feet wet; Laura wandering alone in the dark, sitting down on a park bench and smoking in public; a drive in the country in a borrowed car.
Some scenes are made less ambiguous and more dramatic in the film. The scene in which the two lovers are about to commit adultery is toned down: in the play it is left for the audience to decide whether they actually consummate their relationship. In the film, Laura has only just arrived at Dr. Lynn's flat when the owner returns, and is immediately led out by Dr. Harvey via the fire escape. Later, when Laura wants to throw herself in front of an express train, the film makes this intention clear by means of voice-over narration.
There are two editions of Noel Coward's original screenplay for the film adaptation, both listed in the bibliography.
The 2008 Kneehigh Theatre production was adapted for the stage by Emma Rice and is a mixture of the film and the stage play. It toured the UK before opening in February 2008 at the Haymarket Cinema in London, which was converted into a theatre for the play.
Gray acknowledges a common criticism of the play: why do the characters not consummate the affair? Gray argues that their problem is class consciousness: the working classes can act in a vulgar way, and the upper class can be silly; but the middle class is or at least considers itself the moral backbone of society - a notion whose validity Coward did not really want to question or jeopardise as the middle classes were Coward's principal audience.
However, Laura in her narration stresses that what holds her back is her horror at the thought of betraying her husband and her settled moral values, tempted though she is by the force of a love affair. Indeed, it is this very tension which has made the film such an enduring favourite.
The values which Laura precariously, but ultimately successfully, clings to were widely shared and respected (if not always observed) at the time of the film's original setting (the status of a divorced woman, for example, remained sufficiently scandalous in the UK to cause Edward VIII to abdicate in 1936). Updating the story left those values behind and with them vanished the credibility of the plot, which may be why the remake could not compete.
The film is widely admired for the beauty of its black and white photography and the atmosphere created by the steam-age railway setting, both of which were particular to the original David Lean version.
Another reason for the film's continued admiration is the brilliant performances by the cast. Celia Johnson, Trevor Howard, Stanley Holloway, and Joyce Carey were excellent. The film was an amazing success in the UK and such a hit in the US that Celia Johnson was nominated for an Academy Award for Best Actress.
The film was released amid the social and cultural context of the Second World War when 'brief encounters' were thought to be commonplace and women had far greater sexual and economic freedom than previously. In British National Cinema (1997), Sarah Street argues that "Brief Encounter thus articulated a range of feelings about infidelity which invited easy identification, whether it involved one's husband, lover, children or country" (p. 55). In this context, feminist critics read the film as an attempt at stabilising relationships to return to the status quo. Meanwhile, in his 1993 BFI book on the film, Richard Dyer notes that owing to the rise of homosexual law reform, gay men also viewed the plight of the characters as comparable to their own social constraint in the formation and maintenance of relationships. Sean O'Connor considers the film to be an "allegorical representation of forbidden love" informed by Noel Coward's experiences as a closeted homosexual (p. 157).
The British play and film, The History Boys features two of the main characters reciting a passage of the film. (The scene portrayed, with Posner playing Celia Johnson and Scripps as Cyril Raymond, is the closing minutes of the film where character Laura begins, "I really meant to do it.")
The Channel 4 British drama series Shameless has a plot based on Brief Encounter in its fifth series. Similarities include the main character, Frank Gallagher getting grit in his eye from a bus, being caught by a friend of his wife, and the tearful departure. Frank's wife, Monica even thanks Frank for coming back.
In another nod to Brief Encounter, the 2006 romantic comedy film The Holiday portrays Miles (Jack Black) removing dust from the eye of Iris (Kate Winslet), leading the new acquaintances into a romantic relationship.