James Manning is a prosperous solicitor in London, living a life of comfort with his younger wife, Anne, who is both dutiful and accommodating. They enjoy the perks of their affluent lifestyle, which includes a charming home in the city and a secluded retreat in Buckinghamshire.
During a village cricket match, Anne encounters William Bule, the son of a prominent local family who has just returned from the United States. Eager to enhance their social circle, Anne proposes to her hesitant husband that they invite their neighbors over for drinks. Unfortunately, that evening, James finds himself caught up with work in the city, leaving Anne to host the gathering alone.
The situation takes a tragic turn when a speeding car sideswipes a man riding his bicycle along a village lane. The accident leaves the man—whose identity is later revealed to be Maggie, the couple's housekeeper's husband—seriously injured, and he succumbs to his injuries a few days later. This incident prompts Anne to show a deep concern for Maggie, which James finds difficult to comprehend.
As tensions rise, James discovers a scratch on Bill’s car, leading him to confront Bill over lunch regarding the accident. Although Bill initially refutes the accusation, he eventually confesses and expresses his intention to report the incident to the authorities the following day, despite feeling it may be futile.
Intrigued by the developments, James shares his findings with Anne, who is surprisingly against Bill reporting to the police. Yet, when Anne reveals that she was the one driving the car during the accident, James’s perspective shifts drastically. Initially, she maintains that her visit to Bill was to request more drinks, but ultimately, she confesses to having an affair with him.
As the narrative unfolds, a Buckinghamshire police inspector arrives to question the Mannings and Bill concerning the accident. James faces a moral dilemma: should he uphold the truth or protect their appearance as a respectable couple? His love for Anne remains unwavering, prompting them to retreat to Wales, hoping to escape the weight of guilt, the incident, and their tumultuous marriage. Anne vows to end her affair, yet James is later devastated to discover she has not followed through.
With the investigation ongoing, Maggie, the widow of the deceased, comes forth with crucial testimony, identifying Bill’s car as the one involved in the accident. However, the police express skepticism regarding her credibility as she had been previously dismissed from her job due to accusations from Bill, but Anne had kindly offered her a job after a lengthy period of unemployment.
In a tense meeting, Bill requests that James provide him with an alibi, foreseeing that the inspector will question them soon. Reluctantly, James agrees, weighed down by the pressures of loyalty and justice. When the police inspector approaches him for confirmation of Bill's alibi, James finds himself ensnared in the web of deceit.
As guilt consumes Anne, she confides in Maggie, admitting her culpability in her husband’s death. Devoted to Anne, Maggie subsequently rescinds her police statement, shielding Anne from the repercussions.
The complexities of their relationships deepen when James learns from a relative of Bill that he is gravely ill with cancer. Anne, in a rush of conflicting emotions, returns to care for Bill during his final months, dedicating herself to him for 18 long months until he passes away. In a poignant moment, Bill’s father expresses his gratitude to James, acknowledging Anne's devoted care at the funeral.
Ultimately, James reaffirms his enduring love for Anne as they share lunch together, reflecting on their tumultuous journey before she departs for Bill's London apartment, leaving their story open-ended yet irrevocably changed.
