A quiet domesticated couple, Fred and Norah, live in a London suburb. They have married later in life than most people, but they are devoted to one another for the more lasting qualities of character and integrity. It is Fred's practice to go out for a glass of bitter in the evenings, and on the particular occasion while he is away, Norah has a visitor - a flash-looking young woman named Evie. It appears that some years before her marriage Norah had an illegitmate son, Roy. She has never told Fred, and she has helped the boy from time to time, but he has proved to be weak and spineless and now he in trouble with the police and Evie has been sent to get money out of Norah to aid him in running away. The two women are interrupted by the arrival of a police inspector who tells Norah that he is possession of all the facts, and begs her, for the boy's sake, not to try to shield him. He assures her that if only Roy can be removed from his present companions there is hope for him yet-but only the law can do that. Norah understands but feels the need to convince herself. When the inspector has gone she again admits Evie, this time with Roy, and it is not long before she sees for herself how weak he is, and what a bad influence the girl has upon him. Her mind is made up, and although it distresses her greatly, she hands the two of them over to the police. When Fred returns he finds the inspector alone in the room waiting for him. It is at once clear that he has known all along what was happening; it was in fact he who advised the police; and far from being hurt or angry at Norah's part in the whole story he is proud of the way she has behaved. As husband and wife settle down once more in their chairs each, pretending for the sake of the other, behaves as though nothing has happened during Fred's short absence in search of bitter.