The novel opens in London, where modern young women find themselves facing a distinct scarcity of marriageable men. Madeline Irwin is desperately in love with Rupert Denison, a cultured, rather pedantic dandy who excels in quoting Browning and lecturing on architecture, but who continually offers excuses rather than serious commitments. Madeline shares her anxieties with Bertha Kellynch, an improbably pretty and remarkably perceptive young married woman who has an intellectual passion for studying human character. Bertha is happily married to Percy, a serious barrister with parliamentary ambitions, though Bertha privately longs for more romance and excitement than her comfortable domestic life provides.
Bertha undertakes to help Madeline win Rupert, enlisting the aid of Nigel Hillier, an old admirer of Bertha's. Nigel made the mistake of marrying an heiress for money rather than waiting for Bertha, and now lives in deep misery with his wildly jealous wife, Mary. Nigel is obsessed with Bertha, constantly seeking excuses to see her, while Mary is consumed by suspicion and eventually resorts to sending anonymous letters to Percy in an attempt to ruin Bertha's reputation and separate them.
Meanwhile, Rupert's educational efforts extend to Moona Chivvey, an artistic and loud young woman who serves as a stark contrast to Madeline. Rupert finds himself torn between these contrasting female energies while maintaining his superior, schoolmasterly detachment. Madeline, momentarily despairing, accepts a proposal from Charlie Hillier, Nigel's steady younger brother, but quickly realizes her mistake when Rupert finally awakens to his true feelings and attempts to claim her.
Percy receives anonymous slanders regarding Bertha and Nigel, leading to a tense confrontation where Percy's hidden jealousy and deep love for his wife are finally revealed. Bertha's absolute frankness and calm devotion dispel Percy's suspicions, and the couple achieves a renewed and profound romantic harmony. Mary's jealousy is partially tamed through unexpected counsel from Bertha herself, leading to a fragile domestic peace.
As the narrative concludes, Madeline ultimately marries Rupert after sorting through her romantic confusion, while the various social entanglements resolve into a state of quiet stability. The overarching exploration of marriage reveals that true intimacy requires honest self-reflection, emotional bravery, and the willingness to look beyond the surface of convention.
