In her teenage years, Emily Dickinson forms a deep friendship with Susan Gilbert during a recital at the Amherst Shakespeare Society, leading to a tender romance as they portray lovers in a scene. After sharing a kiss on a stroll, Emily's family departs for a month-long trip, allowing Susan to stay with her during their absence. As their affection grows, they artfully hide their relationship from the prying eyes of others.
When Susan receives a teaching job out west, they engage in an extensive exchange of love letters while she is away. To Emily's dismay, upon Susan's return, she learns that Susan has secretly become engaged to Emily's brother Austin. Susan expresses her regrets, revealing that the marriage is a necessary arrangement for her financial security, allowing them to reside adjacent to Emily without raising suspicion about their romance.
Fast forward twenty years, and Emily and Susan live side by side, their bond undiminished as letters flow back and forth, delivered by Susan's children. Emily shares her collection of poems with Susan, showcasing her creative spirit, often scribbled on scraps and recipe margins, many dedicated to Susan herself. She enjoys nurturing her garden and providing freshly baked bread to neighborhood kids.
However, trouble brews when Susan becomes too occupied to connect with Emily. In her absence, a widowed Kate Scott Turner visits Susan but instead forms an unexpected connection with Emily, staying at her home. Kate's abrupt departure leaves Emily feeling regretful, wishing she could have bid farewell and given Kate the garters she crafted. Susan, feeling a pang of jealousy, notes that Emily has never made her any such tokens.
Emily's social circle includes Judge Otis Phillips Lords, an elderly man who amusingly confuses the Brontë sisters and dozes off during their conversation, leaving Emily feeling inadequate when he describes her as "plain." Just as she offers him assistance, Susan enters, witnessing an awkward moment.
In a significant meeting, Thomas Wentworth Higginson pays a visit to Emily after she expresses a desire to publish her poetry. During their discussion, he outlines the nuances of poetry, particularly emphasizing the distinction between male and female voices in writing. He critiques her work, ultimately advising her that her poems are not yet fit for publication.
Mabel Todd arrives at Emily's place with the intention of playing the piano, only to be informed by the maid that Emily will be upstairs writing while she performs alone. Soon after moving to Amherst, Mabel begins an affair with Austin, openly indulging in their relationship, even using Emily's home to rendezvous while Emily remains discreetly in her room. Mabel proposes publishing their scandalous love letters, but Austin dismisses it as too outrageous and urges her to find another creative outlet.
Tragically, Emily becomes gravely ill and ultimately passes away. Her sister Lavinia is left to prepare Emily’s body for burial. After her death, Mabel uncovers a chest brimming with Emily's poems and letters, only to discover that many intimate pieces were penned to Susan. With Austin's assistance, Mabel embarks on a mission to erase all mentions of Susan’s name, replacing it with male names to mask the true nature of their relationship.
Years later, as Emily's literary legacy flourishes, Mabel delivers a lecture to a large audience of society women, claiming that Emily was an eccentric recluse she only witnessed once — in her casket. Mabel asserts that Emily's poems are meant for the Judge Otis and that she has re-titled them for clarity. Meanwhile, Emily’s niece presents her own talk revealing that Emily and her mother had been secret lovers, but only a handful attend.
The film concludes with informative titles that unveil how recent technological advancements have exposed Mabel's alterations, confirming that the love letters were indeed addressed to Susan, bringing their hidden relationship to light once more.
