Two old friends, Alida Slade and Grace Ansley, are finishing lunch on the terrace of a Roman restaurant and move to the parapet, where they benignly contemplate the magnificent ruins of the Palatine and the Forum. Remarking that the scene below is the most beautiful view in the world, the two ladies agree to spend the afternoon on the terrace. Alida arranges with the waiter to permit them to stay until evening. They hear their daughters, Barbara Ansley and Jenny Slade, departing to spend the afternoon with two eligible young Italian men, and Grace remarks that the young women will probably return late, flying back by moonlight from Tarquinia. It becomes evident at this point that Grace has a closer relationship with her daughter than Alida has with Jenny because Alida did not know where the girls were going. Also, Barbara remarks a bit ruefully to Jenny as the two of them depart that they are leaving their mothers with nothing much to do.
At that point, Alida broaches the subject of emotions by asking Grace if she thinks that their daughters are as sentimental, especially about moonlight, as they once were. Grace responds that she does not know at all about the girls’ sentiments and adds that she doubts that the two mothers know much about each other either. The two women sit silently for a while, thinking about their perceptions of each other.
Alida’s perceptions of Grace are recounted as an interior monologue, which continues throughout the story, interspersed with passages of dialogue. As she reflects, she also reveals the circumstances of the years since she first met Grace. Grace had been married to Horace Ansley shortly before Alida had married Delphin Slade. Alida considered the Ansleys nullities, living exemplary but insufferably dull lives in an apartment directly across the street from the Slades in New York City. They had been superficial friends, and Alida had rather closely observed the irreproachable events of the Ansleys’ lives for a number of years before her very successful lawyer husband made a big coup in Wall Street and the Slades moved to a more fashionable Park Avenue address. She prided herself on the lively social life that she and Delphin enjoyed, and especially on her own skills as a hostess and a brilliant personality. Both women were widowed only a few months before the time of the story and have renewed their friendship in the common bond of bereavement.
Alida’s envy of Grace, despite her disparaging assessment of her, emerges in her thoughts at this time. She wonders how the Ansleys could have produced such a vivid and charming daughter, when her own Jenny seems by comparison so dull. She recalls that Grace was exquisitely lovely in her youth as well as charming in a fragile, quiet way. She reflects that she herself would probably be much more active and concerned if she had Barbara for a daughter.
Grace, for her part, has a mental image of Alida as a brilliant woman, but one who is overimpressed by her own qualities. She remembers Alida as a vivid, dashing girl, much different from her pretty but somewhat mousy daughter. She views Alida’s life as sad, full of failures and mistakes, and feels rather sorry for her. Thus, in part 1 of the story, the setting, the situation, and the attitudes of the two women are presented in a manner that suggests a placid, if superficial, friendship of many years’ standing, with both of the women secretly feeling some pity for each other’s past life.
Part 2 begins with the tolling of the five o’clock bells and the decision of the two women to remain on the terrace rather than going in to play bridge. As Grace Ansley knits, Alida Slade reflects that their own mothers must have had a worrisome task trying to keep them home safe despite the lure of the romantic evenings in Rome. Grace agrees, and Alida continues with speculations about the probability that Barbara will become engaged to the attractive, eligible young Roman pilot with whom she is spending the evening, along with Jenny and the second young man. Jenny, Alida reasons, is only a foil for Barbara’s vivacious charm, and Grace may be encouraging the companionship for that very reason. She tells Grace of her envy, stating that she cannot understand how the Ansleys had such a dynamic child while the Slades had such a quiet one. Alida recognizes in her own mind her envy, and also realizes that it began a long time ago.
As the sun sets, Alida recalls that Grace was susceptible to throat infections as a girl and was forced to be very careful about contracting Roman fever or pneumonia. Then she recalls a story of a great-aunt of Grace, who sent her sister on an errand to the Forum at night because the two sisters were in love with the same man, with the result that the unfortunate girl died of Roman fever. Alida then reveals that she used a similar method to eliminate the competition she believed existed between herself and Grace when, as young women in Rome, they both were in love with Delphin Slade. She cruelly reveals that she wrote a note to Grace imploring a rendezvous in the Colosseum by moonlight, and signed it with Delphin’s name.
Revealing her hatred further, she gloats about how she laughed that evening thinking about Grace waiting alone in the darkness outside the Colosseum, and how effective the ruse had been, for Grace had become ill and was bedridden for some weeks. Grace is at first crushed to learn that the only letter that she ever received from Delphin was a fake, but she then turns the tables on Alida by assuring her that she had not waited alone that night. Delphin had made all the arrangements and was waiting for her.
Alida’s jealousy and hatred are rekindled as she realizes that she has failed to humiliate Grace Ansley, especially when Grace states that she feels sorry for Alida because her cruel trick had so completely failed. Alida protests that she really had everything: She was Delphin’s wife for twenty-five years, and Grace has nothing but the one letter that he did not write. In the final ironic epiphany, Grace simply replies that she had Barbara. Then she moves ahead of Alida toward the stairway.
This battle of the two women for the integrity of their own status with respect to the man they both loved ends with the complete victory of the woman who has appeared to be the weak, passive creature. She moves ahead because she is now dominant. The source of Barbara’s sparkle is now revealed, and Grace is also now shown to be a woman who defied conventional morality and social restrictions to spend a night with the man she loved. Alida Slade is left only with the dismaying knowledge that she, in her attempt to be hateful and cruel, actually brought about the meeting that produced the lovely daughter she envies her friend having.