Set in Edwardian London, the film centers around Philip Marshall, a mild-mannered, middle-aged man stuck in a miserable marriage with his nagging and abusive wife, Cora. Despite his reputable position as a store manager, his home life is anything but fulfilling. Philip finds solace in an unexpected friendship with Mary Gray, a young, gentle stenographer who walks into his shop seeking employment. Their friendship quickly blossoms into a tender, innocent love affair, providing Philip with a glimpse of the happiness he longs for.

However, the constraints of society and his marriage to Cora create immense pressure on Philip. As their bond grows deeper, the complications and potential consequences of his emotional entanglement with Mary begin to surface. Meanwhile, Cora becomes increasingly suspicious and vindictive towards Philip, threatening to expose and ruin him. The escalating tensions lead to a chain of dramatic events that force Philip to make dire decisions regarding his future and the people he cherishes.