In 1969, three years after her first novel, the gloriously pulpy Valley of the Dolls, became a towering number-one blockbuster on a bestseller list dominated by names such as Michener, Wouk, and le Carré, Jacqueline Susann, with thickly rimmed eyes, signature lacquered black hair and in a print mini-dress, went on the David Frost talk show. There, the notoriously scabrous critic John Simon eviscerated her before a live audience. What was Valley of the Dolls, he asked her, but “a piece of trash on which you can get famous, rich, known quick, and make money?” Smiling gamely and (literally) leaning in, Susann, then 50, asked him if his name was Goebbels, Göring, or Simon, “because you sound like a stormtrooper.” She then told him Valley of the Dolls was “too sophisticated a story for you to understand, because it’s dirty!”

But that just propelled Simon to new heights of rage. When the critic Rex Reed, also on the show alongside a young Nora Ephron, disclosed that Simon had told him he’d read merely 30 pages of the novel, Simon said, “How many swallows of rotten stew do I have to swallow before I puke and know that this is inedible?”

“I am thrilled that you went to Harvard,” Susann shot back, still grinning. Then the clincher: “Tell me, what have you written?” She thought she’d had the day’s last word. But later that night, watching The Tonight Show, she would hear Truman Capote call her “a truck driver in drag.”

It’s hard not to watch both moments without feeling intensely protective of Susann, of wanting to be on #TeamJacqueline. Here was a woman who not only was enraging the male literary establishment by making a fortune giving readers, with laser precision, exactly what they wanted, but who also—unbeknownst to nearly everyone—had, decades ago, birthed a son who was severely autistic. Devastated by his inability to share affection with her, she put him in an institution for life. Moreover, only seven years before Valley’s success, she had survived breast cancer and a mastectomy. Upon recovery, she’d made a deal with God: If He would just give her another decade of life, she would become a literary celebrity. Susann, it seemed, had been dealt blows only to come out of them stronger, her appetite for living—and for recognition—sharpened.

She got her wish from Valley of the Dolls, not least because she hand-sold it to booksellers with a thoroughness that would pave the way for the modern book tour. (She would have two more salacious No. 1 bestsellers, The Love Machine and Once is Not Enough, before cancer recurred, taking her life in 1974.) Valley, shockingly matter-of-fact for its time about everything from premarital sex, cunnilingus, and homosexuality to abortion, addiction, cancer, and narcissistic personality disorder, situated Susann in a lineage of (mostly) female authors of wildly popular and stylistically unfussy bestselling potboilers, including Edna Ferber (Show Boat), Margaret Mitchell (Gone with the Wind), and, later, Judith Krantz, Jackie Collins, and E.L. James (50 Shades of Grey). The book also became a 1967 film that has since become a camp classic, full of lines that many gay men of a certain age can recite by heart. (“You know how bitchy fags can be.”)

But how does Valley of the Dolls actually hold up as a read 50 years later? Incredibly well, in fact, if you’re not looking for nuance and shading. Susann bothers little with phrasing or mood. For her, language is a blunt instrument to move a story forward—mostly through straightforward and often hilarious dialogue. And Valley’s main three heroines, who become friends as young strivers in postwar New York City—the WASP-y, well-bred, overly altruistic New England beauty Anne Welles; the brash, fame-hungry vaudeville urchin Neely O’Hara; and the Marilyn Monroe–like bombshell with a childlike heart of gold Jennifer North—provide a rich stew of wide-eyed ambition in their early years that propels the first half of the book forward. They want urban excitement, good sex, financial prosperity, to love and to be loved for who they really are, and, eventually, children. Hardly anyone in Valley, men included, wants any vocation outside of showbiz fame or the money that comes with engineering it. Written in the decade of Gloria Steinem and Betty Freidan, the book doesn’t frame women’s needs as particularly complex or revolutionary. Its power derives from the fact that, unlike in the usual male literary landscape, the women are not only objects of desire but agents of it—and that, like real people, they want more than one thing at the same time. It was hard to reread Valley of the Dolls and not think about Mad Men’s Peggy Olson and Joan Holloway, juggling work, lovers, family, and (eventually) children, all the while drinking and chain-smoking.

The book is also extremely attuned to their financial security, with long passages devoted to their savings or their wise investments. Valley of the Dolls depicts a world where men and women alike go to bed (or, in Susann’s hard-boiled, vaudeville-era slang, “the kip”) with people as career moves, but almost from its opening pages, it stresses the importance of a woman’s growing a nest egg of her own (even if that nest egg is masterminded by the loving father-figure character of talent agent Henry Bellamy). Amid its depravities, it’s a highly practical book.

When Valley reveals its meanings, it does so casually, with a throwaway line here or there. One of them is a depiction of New York as a land of liberation, freeing Anne from the snootiness of smalltown Lawrenceville, Massachusetts, as much as it freed Susann from her hometown of Philadelphia. “There was an acceptance at face value in New York,” she wrote, “as if everyone had just been born, with no past heritage to acknowledge or hide.” Another, likely honed through Susann’s brush with death via cancer, is the idea of time, the present moment, as precious. “I want to be aware of the minutes and the seconds,” says suave literary ladies’ man Lyon Burke. “To make each one count…because time is life. It’s the only thing you can never get back.”

The other casually offered subtext is lesbianism. Legendarily, Susann—happily married, until her death, to her manager, publicist, and closest companion Irving Mansfield—had affairs or infatuations with numerous women throughout her life, notably Ethel Merman, upon whom the brassy, lusty middle-age Broadway diva Helen Lawson is clearly based. The passages in which classy, demure Anne Welles falls “into friendship” with Lawson are among the book’s most sensual and tender. “Helen’s magnetism did not rely on her face or figure,” Susann wrote. “There was something that compelled you to watch her, and soon you forgot the wide waistline, the sagging jawline, and felt only her tremendous warmth and rakish good humor.” Reflecting its time, Valley of the Dolls is obsessed with the physical deterioration of women, for whom age is “a hatchet that vandalize[s] a work of art.” Given that, the most truly erotic aspect of this sex-filled book might be Susann’s vision (via Anne) of the middle-aged, overweight Lawson as an earthy and desirable being.

Ultimately, Valley of the Dolls can probably not be called a feminist book. A certain female vitality and optimism that animates the beginning of the book devolves into familiar midcentury tropes by its end: that a woman can’t find passionate love and stable companionship in the same person; that her value in society diminishes with every passing year and the emergence of every tiny wrinkle; that she either stakes all her identity and happiness on one man who cannot fully love her for who she is (Anne and Jennifer); or that she is a man-eating monster (Helen and Neely).

The only true gift Valley gives its women is one another’s friendship—not to everyone, not all the time (there are almost preposterous betrayals), but much of the time, and when it’s needed most. The best, truest scenes are the ones where Anne, Helen, Neely, and Jennifer are simply shooting the shit over drinks and cigarettes, giving (sometimes blunt but always sincere) life advice and affectionately teasing one another. Its depictions of female friendships have the warmth and texture of real life.

It can be embarrassing to say one finds true feeling in a book like Valley of the Dolls, where desire and motivation are dialed up to preposterous levels. But then there is a scene like this, shortly before Jennifer’s cancer diagnosis (with both cancer and her autistic son, Susann took the pain she wouldn’t dare speak of in life and plowed it into her fiction):

“Oh, come on now, Jen. All of Europe loves you… and now you’ve got America as well.”

“They love my face and body. Not me! There’s such a difference, Anne.” Then she shrugged. “Maybe I’m just not very lovable.”

“I love you, Jen—really.”

Jennifer smiled. “I know you do. It’s a pity we’re not queer—we’d make a marvelous team.”

Racing against time for fame, Susann knew how to give readers what they wanted: a shockingly contemporary page-turner that went deep into the stuff of taboo, but still adhered to old scripts of women suffering virtuously in their undying love of men. Valley of the Dolls’s deepest and most moving taboo is its queerness—and its frank depiction of friendships among female go-getters who celebrated one another’s successes and offered one another love and companionship when they hit the hard place between happiness and the heterosexual ideal.