At the beginning of Overtones, Harriet is preparing for the arrival of a former acquaintance, Mrs. Margaret Caldwell, whom she has invited to tea. She is also having a discussion with her primitive ‘‘inner self,’’ Hetty. The two women establish that they are indeed very different parts of the same person. As Hetty notes, ‘‘I’m crude and real, you are my appearance in the world.’’ Harriet concedes that they are one and the same, but refuses to admit that Hetty is also the wife of Charles Goodrich. Harriet asserts that she alone is Charles’s wife because it is she who manipulates him and manages him through her social airs and artifice. Eventually the conversation turns to John Caldwell and to Hetty’s despair over not having married him when she had the opportunity. Harriet reminds her that John’s desire to be a painter made for too uncertain a future and that, ‘‘It was much safer to accept Charles’s money and position.’’ Hetty then begins to coach Harriet on what she must say and do when John’s wife Margaret arrives. She is to make sure that Margaret knows she is rich, and should try to make her jealous. Harriet then decides she will make Margaret ask if John can paint her portrait. She will then have the opportunity to make him fall in love with her again.

Margaret arrives with her primitive counterpart, Maggie. Immediately, Hetty tries to goad Harriet into mentioning how rich and influential she is. Harriet resists Hetty’s prodding, however, and greets Margaret sweetly and politely. Maggie instantly faces off with Hetty and the two trade insults and each tries to get the truth out of the other. All the while Harriet and Margaret continue their pleasant conversation, complimenting each other and affirming how wonderful their respective lives have turned out. Maggie admits that Margaret is starving because John has no orders for paintings. When Harriet offers tea, Maggie makes sure Margaret takes it with cream because it is ‘‘more filling.’’ The pleasant chit-chat between Harriet and Margaret continues, while Hetty and Maggie return to prodding their respective counterparts to try and win the game and obtain what they want. Harriet gives in a bit and casually lets drop she has an automobile and a chauffeur. Margaret also gives in to Maggie and brings up the subject of John perhaps painting Harriet’s portrait.

The subject then turns to John’s time as a painter in Paris. Margaret speaks as if John has become an artist of great renown, while Maggie admits that John is actually drawing advertisements and is ‘‘growing weak with despair.’’ Hetty and Maggie finally get down to business once the conversation turns to the subject of Harriet sitting for a portrait done by John. Hetty vehemently urges Harriet to negotiate a low price, while Maggie warns Margaret to be careful not to lose the opportunity. Finally, it is agreed that John will paint Harriet, and with that, both women think they have won. Throughout the entire conversation Harriet and Margaret have remained reserved, with a false air of polite decorum, while Hetty and Maggie have become more and more desperate. In the final moments of the play, Hetty and Maggie face off viciously, each vowing to ‘‘rob’’ the other and take what they covet the most. After a cymbal crash and a brief blackout, Harriet and Margaret end their conversation with false niceties by telling each other what a pleasant time they have had and bidding each other a sweet ‘‘goodbye.’’