Late in the novel Ex-Wife, a pair of newlyweds turned sudden divorcees gather for a final dinner. Peter and Patricia are both somewhat battle-worn: after their lopsided open marriage came to drunken blows, Peter took up with a series of other women and moved out, while Patricia refused to formally divorce him. Unkind words were exchanged, and each had a habit of drunk dialling the other and suggesting doomed lunches or even more doomed sex. Someone was thrown through a glass door. Now, things are calmer. After a few wistful remarks and rather more Tom Collinses than is prudent, it’s time for Peter to call his former wife a taxi. As he leaves the room he pleads: “For God’s sake, think of something flippant for your parting speech, darling. I have thought of mine.” When he returns, both their efforts falter (having the last word is not always the pleasure it’s made out to be). But perhaps this is inevitable: how to sum up the end of a marriage?

One of the many successes of the book is that it doesn’t really try. Patricia, its narrator, equivocates and changes her mind, doubts herself and tells different versions of her partnership and its ending to different audiences for different reasons. The result is a moving, funny and at times disquieting portrait of a woman shocked by the end of something she thought would last for ever. Reading Ex-Wife as one myself, I was struck by our similarity of experience, despite the nearly 100 years separating Patricia’s divorce and mine. Here were the familiar flailing efforts at self-improvement, the disastrous dates repackaged as fun anecdotes for friends with fiances, the expensive facials one cannot really afford, the histrionic tirades about how Love is Irrevocably Broken. Among the alarmingly relatable humiliations and miseries, there were familiar triumphs, too: a near-manic night on the town with a fellow single friend, a perfectly timed comeback in an imagined argument, a flicker of self-belief on the walk home, those early flirtations that gesture at the possibility that another human being might one day desire and even love you.

Parrott’s ability to flit between high and low, light and dark, is well suited to her novel’s backdrop: the glittering yet sinister world of 1920s New York. Ex-Wife was released in the summer of 1929, months before the stock market crash that shook the country, at a time when American culture was flirting with a new modernity but still shaking off its Victorian overskirts. Stigmas surrounding divorce, premarital and extramarital sex, and women in the workplace, were fading but not gone; the novel, released anonymously in a deliberately suggestive paper-wrapped cover, trafficked in all these and more, including alcoholism, spousal abuse and abortion. The book was sold as a celebration of the 20th-century’s new woman: she who drank in speakeasies, danced in nightclubs and juggled her career with an array of suitors.

Its release was scandalous, and purposefully so. Published anonymously as a marketing gimmick, the papers called it “a sensational book about husbands and sex”. After a flurry of media speculation regarding its authorship, fashion writer (and real-life ex-wife) Ursula Parrott was outed by a gossip column, causing another round of press, with headlines like “Fiction or confession?” that will be familiar to anyone who has read reviews of female novelists’ work, even today. Though Parrott insisted Patricia was a composite figure, inspired by herself and other young women in similar circumstances, she bore a striking resemblance to the bobbed young flapper on the cover, and the association between the book’s glamorous, troubled narrator and its glamorous, troubled author stuck.

Born Katherine Ursula Towle in Boston in 1899, the girl who would become Ursula Parrott harboured dreams of writing from her student days at Radcliffe. “Kitty”, as she was then known, had mediocre grades but no lack of style. In the way of many young women familiar with their passions but not, for various reasons, their ambition, she married what she wanted to be: a reporter. The marriage was not a happy one; her husband Lindesay Parrott had made childlessness a condition of their union, wanting to focus on his career and enjoy the new freedoms afforded by the postwar period and their adopted home of New York City. But these freedoms were not distributed equally. It was still illegal to take or even distribute information about birth control, and Ursula became pregnant in 1923, shortly after their wedding. She retreated to Boston, where she gave birth in secret, named the baby Marc and left him to be raised by her parents and sister. Two years later, Lindesay discovered the existence of his son and divorced his wife.

Suddenly a single mother fending for herself financially, Parrott could no longer afford not to write. Blacklisted by her well-connected journalist ex, and struggling to be taken seriously by misogynist editors, Parrott resorted to the much-maligned genre of “women’s fiction”, turning out the story of Patricia, a young copywriter trapped in the purgatorial period between her marriage’s emotional ending and its legal one. Filled with beautiful descriptions of clothing and cosmetics, and laced with acidic one liners about booze and bad boyfriends, Ex-Wife struck a nerve. It was an immediate bestseller, shifting more than 100,000 copies in its first year of publication. Hollywood shined up the novel’s darker corners, repackaged it as the more audience-friendly The Divorcee, and released it as a hit film that won Norma Shearer an Oscar for the titular role. Parrott became an overnight sensation and worked hard to make the most of it. Over the next 20 years, she stubbornly carved out a name for herself in numerous works of fiction and short stories, in addition to magazine articles and film scripts, becoming a millionaire with a large following and ever-growing body of work.

But happiness did not come as easily as writing. Despite amassing a substantial fortune, Parrott died in hiding and in deep debt, having been arrested multiple times, once for “impairing the loyalty and discipline of America’s fighting forces” (she had tried to sneak a young soldier out of his barracks to take him to dinner). Three more ill-conceived marriages were followed rapidly by three more divorces, and her relationship with her son – whose maternity she only acknowledged seven years into his life – remained strained. Her abortions, alcoholism and other assorted scandals were mocked ruthlessly by the press. The public derision got worse as she aged, fulfilling the prophecy of her earlier writing on “Leftover Ladies”, her term for the female victims of a society that pitted older women against their younger peers. She spent her final years in various hotels, taking lovers, skipping deadlines to drink and walk her dog (a poodle named, incredibly, Ex-Wife), and amassing unpaid bills as she burned through her fortune. Beset by romantic and financial scandal, her commissions and work relationships dried up. After allegedly making off with $1,000 of a friend’s silverware during a house stay, she spent her last years hiding from an arrest warrant, dying alone of cancer in a charity ward at the age of 58.

In light of her life’s trajectory, it’s perhaps unsurprising that Parrott’s view on the new world and the new paths available for women within it was less than optimistic. “I am not a feminist,” she told Photoplay magazine in 1931. “In fact, I resent the feminists – they are the ones who started all this.” In Ex-Wife, Patricia mirrors her creator’s scepticism in her wry observations on the allegedly liberated ways the modern man and woman loved and made love. “Men used to buy me violets,” she says. “But now they buy me scotch.” Patricia’s world is full of cab rides in the park, of flirting in fancy hats and strong cocktails at raucous parties, but Parrott draws just as vividly those same parties after the third, sixth and 16th drink: the precarious economic position of women only professionally viable while still considered sexually so; the callousness and even violence of men no longer bound by old rules of decorum.

The book is not so much a celebration of the unconventional woman as it is a roadmap of the dangers that might befall her. Parrott is a warts-and-all chronicler of her world as it is, but Ex-Wife is also scattered with glimpses of the world as it could be: full of supportive friendships, unconventional living arrangements, acts of stunning generosity between women, and even the kindness of a few gentle men. Though beautifully rendered, these are not the focus of the novel. Indeed, Patricia ends the book not as a new kind of woman, but one she has already been: someone else’s wife, ready to try again with her eyes more open. Having lost another love and accepted the proposal of a wealthy man who promises to respect if not romance her, Patricia and her friend Lucia consider her new life – and the gorgeous fur coat her fiance has bought her: “‘That’ll be alright, I suppose.’ She ran her finger down the ermine cloak. ‘It might be labelled “Success in the American edition”, Patricia.’”

A hundred years later, and “Success in the American edition” still feels difficult to define, particularly where heterosexual romance is concerned. Certainly, Parrott herself never felt she found it, despite her multitudinous professional achievements, and the hard-won, unconventional life she carved out for herself. Ex-Wife should have been the jewel in her crown: a precursor to modern autofiction as relevant, moving and scathing today as it was the day of its publication, a quintessential expression of Carrie Fisher’s suggestion to “take your broken heart and make it into art”. Though Parrott’s heroine compromises on a marriage of convenience, and Parrott herself ended up a “Leftover Lady”, Ex-Wife exists now as a testament to the other possibilities the turn of the century afforded women, not least among them the ability to speak frankly about the world as it was. Through her novel, Parrott has achieved something she couldn’t imagine for her heroine, let alone herself: the contested comfort of the last word.