Between February 18, 1960, and February 4, 1963, a week before Sylvia Plath committed suicide, at the age of thirty, she sent a series of candid letters to her close friend and former psychiatrist, Ruth Beuscher. What has happened to these documents in the intervening years is a case study in Plath’s legacy. In the nineteen-seventies, fourteen letters, which cover in detail Plath’s estrangement from her husband, the English poet Ted Hughes, were passed from Beuscher to Harriet Rosenstein, a feminist scholar who was working on a biography of Plath. Stymied by the Plath estate, Rosenstein never published the book, and the letters, unknown to the public, remained in her files. In 2017, they were put up for sale by an American book dealer. Images of the letters, with passages clearly legible, were posted online; as rumors about their contents spread, Smith College, Plath’s alma mater and home to a collection of her papers, filed a lawsuit. The case was settled, the letters went to Smith, and Frieda Hughes, Plath’s daughter and literary executor, who had only recently learned of their existence, reviewed them for possible publication.

Plath used letters, often brilliantly, to master appearances. “I am the girl that Things Happen To,” she wrote to her mother, when she was twenty. “I have spent the morning writing a flurry of letters: all sorts, all sizes: contrite, gay, loving, consolatory.” The fact that she could toggle among these conflicting moods, then boast about it, all in a single morning, suggests how important letters were to her sense of herself as adaptable and presentable, whatever the occasion. The hundreds of missives that she sent home to her mother, almost invariably peppy, beginning when she was a seven-year-old away at her grandparents’ house and ending just a week before her death, are the most continuous thread running through “The Letters of Sylvia Plath” (Harper), which has been published in two volumes: the first in 2017, the second this November. But the Beuscher letters, included in the new volume, are different; they are among the most revealing pieces of prose that Plath ever wrote, in any genre. In them, she alleges that Hughes “beat me up physically” a couple of days before a miscarriage, “seems to want to kill me,” and “told me openly he wished me dead.” In a foreword to this volume, Frieda, who was not yet three when Plath killed herself, maintains, “My father was not the wife-beater that some would wish to imagine he was”:

What, I asked myself, would qualify as a physical beating? A push? A shove? A swipe? The assault had not warranted a mention in [an] earlier letter when my mother had written there was “No apparent reason to miscarry.” But of course, now that the relationship was disintegrating, what woman would want to paint her exiting husband in anything other than the darkest colours?

The “context,” she continues, “is not only important, it is vital ”: Plath had torn up a stack of her husband’s papers, and she herself admitted that his outburst was an “aberration.” Frieda writes, “My mother had hit out at the thing they both knew was most precious—typescripts of their own work.”

A letter tells only one side of the story. Plath’s letters to Beuscher, whom she stiffly addresses as “Dr.” throughout, sometimes assume the tone of a psychiatric appointment, where candor and speculation, fact and hunch, are twinned. But their transparency is arresting; these are the only letters in the book where Plath sets aside the kaleidoscopic genius of her style in favor of the plainest possible account. And it is fully consistent with what has long been suspected about Hughes and Plath’s relationship that he might have assaulted her. Since the night they met, as two aspiring writers in England—Plath, fresh out of Smith on a Fulbright; Hughes, a loamy Yorkshire giant—violence was distressingly adjacent to the sexual charge. Plath’s description of that meeting, at a Cambridge University party, in 1956, is among the most famous passages in her journals:

I was stamping and he was stamping on the floor, and then he kissed me bang smash on the mouth and ripped my hairband off. . . . And when he kissed my neck I bit him long and hard on the cheek, and when we came out of the room, blood was running down his face.

Soon she was writing to a college friend that Hughes was “the only man I’ve ever met whom I never could boss; he’d bash my head in.”

It is no surprise that Plath’s clear account of Hughes’s alleged assault gets caught in the briar thicket of conflicting interests. Here is a letter to a friend who was once her psychiatrist, analyzed by a daughter who hardly remembers her mother, and who seeks to exonerate her father. Given Frieda’s suggestion that violence might be an understandable reaction to the ripping up of her father’s papers, it is ironic that we cannot consult all of Plath’s journals, where she was often extravagantly confiding: Hughes notoriously destroyed one of the volumes—in an effort, he said, to spare his daughter and son the pain of reading it. He claimed that a second notebook had mysteriously vanished.

As her letters, more than any other documents, reveal, Plath monitored life from behind a façade of chipper enthusiasm. Her genius took shape hidden by this screen, and when it flowered, especially in “Ariel,” the book of poems that she wrote in the months leading up to her suicide, it was sharp, chilling, and prosecutorial. Plath was always two or more people. She was a product of “the fearful, double-faced fifties,” as Janet Malcolm put it, in “The Silent Woman” (1994), and she has since become perhaps the premier symbol of that decade’s complicated psychological bargains. After her death, she was refracted through the interests of her admirers, or, too often, of her antagonists’ antagonists: widespread hatred of Hughes, which crested in the seventies, sometimes eclipsed an appreciation of her work, in all its furious wit, abrupt tenderness, and transgressive force. In solidarity with Plath, her fans repeatedly vandalized her tombstone, chiselling Hughes’s surname out of the granite. Because Hughes was so entangled in her tragedy—and, in turn, in her legacy—defending her sometimes meant defacing her.

Even “Ariel” was affected: though Plath had left a complete manuscript on her desk, Hughes altered the contents for publication, in 1965, in ways that struck many readers as self-absolving. A “restored” version, preserving Plath’s apparent wishes, was published in 2004. Some readers applauded the justness of the restoration, while still preferring Hughes’s version—the one that hit American literature like a meteor when it first appeared. The preference had to be carefully expressed: its implications for a woman’s agency were troubling.

The fiftieth anniversary of Plath’s death came and went in 2013. Almost all the major players in this story are now dead. Plath’s mother, Aurelia, published her own, highly selective edition of Plath’s correspondence, “Letters Home,” in 1975, and died in 1994. After Plath’s death, Hughes raised their two children, remarried, became the British poet laureate, and, for the most part, kept his silence about Plath. Just before he died, of cancer, in 1998, he published a book of elegies for Plath, “Birthday Letters,” which was received as either tender or tactical, depending on whose side you took. Ted’s sister Olwyn, who clung to her brother and clashed with Plath, died in 2016. Nicholas Hughes, the baby whose gravity-defying crib gymnastics are heartbreakingly described in “Ariel,” became a fisheries scientist in Alaska and, in 2009, hanged himself. Frieda, a poet and painter living in Wales, survives.

Though the main stakeholders in this saga have petered out, for most of Plath’s readers a vexed affinity endures. When I discovered Plath in high school (as many still do), I remember the feeling of being an interloper in a totally absorbing story. Now I often teach her poems, but rarely read them aloud; it is too absurd to hear a man say the lines “I rise with my red hair / And I eat men like air.” And yet, on many errands across town, here in Wellesley, Massachusetts, I detour past Plath’s childhood home, a small white Colonial, unencumbered by any marker or plaque. It looks much the same as it did one summer day in 1953, before Plath’s senior year in college, when she first attempted suicide, burrowing into a crawl space with a stomach full of pills and, as she writes, in “Lady Lazarus,” “rocked shut / As a seashell.” Much of the best writing about Plath suggests the ways in which she both attracts and forbids a reader’s identification, with Malcolm’s book at the very top of the list. This spring, Plath and Hughes’s private possessions, including books, typewriters, and wooden chairs, as well as Plath’s tartan kilt and yellow frock, were auctioned in London. Some items went to well-known writers and Plath scholars. Peter K. Steinberg, an archivist and one of the editors of her letters, got her fishing rod. The dispersal of her things suggests that Plath’s story, controlled so tightly for so long, has finally begun to come unknotted.