Following her graduation, Karen Wright and Martha Dobie decide to turn Karen’s family farm in Massachusetts into a private boarding school for girls. Despite being newcomers to the area, they manage to recruit students with the help of Amelia Tilford, a wealthy woman who not only enrolls her mischievous granddaughter, Mary Tilford, but also encourages other families to send their daughters to the school. Just before the school’s opening, Martha’s aunt, Lily Mortar, arrives unexpectedly and insists on a teaching position, using the opportunity to continue living off Martha’s generosity.
As the school begins to operate, romantic tension develops between dr. joe cardin and Karen, though neither is initially aware that Martha harbors feelings for him. The relationship between Joe and Karen deepens, with their budding romance blossoming amidst the daily routines of the school. One evening, Joe falls asleep in Martha’s room while waiting for Karen to return, leading to a vulnerable moment. He wakes suddenly, unintentionally breaking a glass, which startles Mary Tilford, who has been covertly observing from the shadows. Before leaving, Joe casually mentions his plans to marry Karen, unaware that Mary is eavesdropping. Later, Martha quietly sheds tears, heartbroken by the secrecy and unspoken emotions swirling around her.
Trouble escalates when Karen disciplines Mary for skipping classes and lying, prompting Mary to fake an illness. When Karen and Martha examine her, Joe is called in to check on Mary. Meanwhile, Martha reaches a breaking point with Aunt Lily, who is ineffectual and disrespectful. Martha fires her, but Lily, feeling insulted, confronts Martha about her true feelings for Joe, suggesting romantic interest. During this confrontation, Martha overhears Rosalie Wells and Evelyn Munn—Mary’s roommates—listening behind a door, and in her flustered state, she accidentally injures Rosalie’s arm.
Feeling misunderstood and isolated, Mary decides to run away. Her grandmother, Amelia, initially suggests that the girl return home. However, Mary, determined to protect her own reputation, distorts the truth about Martha and Joe—accusing them of an affair—and even falsely claims Martha intentionally injured Rosalie. She coerces her grandmother into talking to Rosalie, threatening to reveal that Rosalie stole a bracelet. In her fabricated story, Mary claims Martha and Joe's relationship was inappropriate, and her grandmother, shocked by these revelations, reacts by pulling her daughter’s schoolgirls out.
The scandal results in a lawsuit for slander against Amelia, which Karen, Martha, and Joe lose. The fallout is devastating: the school can no longer attract students, Joe loses his hospital job, and Lily leaves after feeling betrayed. Joe then proposes they all move to Vienna, where he has secured a new position. Karen hesitantly agrees, but when Joe mentions that Martha might come along too, Karen, feeling hurt and betrayed, questions whether there was any real romance between Martha and Joe. She ultimately tells Joe to go alone, still unsure of his honesty.
After Joe departs, Martha confesses that she loves him but never told him. She then boards the same train as Lily, who mentions seeing Mary and Rosalie with the missing bracelet. Martha immediately realizes what has transpired and what Mary has done. She rushes off the train and convinces Rosalie to tell the truth. Though Amelia offers Martha compensation, she declines, only asking that Amelia tell Karen to stay with Joe, wherever he might be. Martha departs, leaving behind the hurt and betrayal, while Amelia informs Karen of everything. Determined, Karen then goes to Vienna to be with Joe, seeking her own closure and the chance to rebuild her life.
