“A woman cannot be herself in the society of the present day, which is an exclusively masculine society,” Henrik Ibsen wrote in 1878, proving himself, in 2017 parlance, to be a woke bae. He was writing about “A Doll’s House,” his proto-feminist masterwork, which concludes with Nora Helmer, a restive Norwegian housewife, walking out on her husband, Torvald. The play ends with a slamming door, one of dramatic literature’s greatest cliffhangers.

Enter the playwright Lucas Hnath, who has, fourteen decades later, written a sequel. In “A Doll’s House, Part 2,” which has been nominated for eight Tony Awards, Nora (played by Laurie Metcalf) returns fifteen years later, having written a popular anti-marriage novel under a nom de plume. “It’s something I’d been threatening to do for a while, to write a sequel to ‘A Doll’s House,’ ” Hnath, a thirty-seven-year-old with Jim Morrison hair, said recently. “There’s something about just saying that that sounded so audacious.”

Hnath grew up near Orlando and read the play in high school. His mother bore some resemblance to Nora: she was divorced and, as an ordained minister, was a woman in a man’s world. After moving to New York, Hnath saw an avant-garde production in which Nora had a lizard tail. “I came out of that thinking, That was a terrible production, but that play’s kind of good,” he recalled. In 2014, while travelling through Croatia by bus, he copied a bad translation onto his laptop and began writing his own adaptation. “By the time I got to the end of it, I felt the need to keep going.”

But he needed help. In workshops, he polled the actors about how they imagined Nora’s single life. Everyone assumed the worst: prostitution, debtors’ prison. So Hnath went in the opposite direction, making her a successful author. He researched nineteenth-century Norwegian divorce law and read books such as “Ibsen: The Dramaturgy of Fear” and “Marriage, a History.” Still, he said, as a man, he worried. “I wondered, Am I missing something?”

That’s when his producer, Scott Rudin, proposed a playwriting method you might call dial-a-feminist. Hnath reached out to several academics, including Susan Brantly, who teaches Scandinavian literature at the University of Wisconsin-Madison, and Toril Moi, an Ibsen scholar at Duke and the author of “Sexual / Textual Politics: Feminist Literary Theory.” In one draft, Nora argued that she left because it was better for the children; Moi wrote to Hnath, “You could get some traction here by enforcing the idea that not all women are made to be mothers. . . . This point of view is still shocking to some feminists.”

The other night, two of Hnath’s consultants caught the show, at the Golden Theatre. They were the New York University psychologist Carol Gilligan, best known for her research on female moral development (“In a Different Voice”), and the Princeton literary theorist Elaine Showalter, who coined the term “gynocritics” (“Toward a Feminist Poetics”). “Carol, we’re in the program!” Showalter said, as they took their seats in Row E.

After the show, they got dinner at Joe Allen and discussed. “Tremendous!” Showalter said. “I thought it was going to be ‘Helmer vs. Helmer.’ ” Among the questions they had received from Hnath: Could Nora be sympathetic if she had left her children? “I thought that the audience reaction tonight said ‘No,’ ” Gilligan said—the crowd had cheered for Nora’s daughter during a heated exchange. In her research following Roe v. Wade, Gilligan had interviewed pregnant women who were considering abortion. “The word ‘selfish’ kept coming up,” she said. “There was this notion that the ‘good woman’ is selfless. So, according to that, Nora’s a bad woman.”

Showalter had advised Hnath to read up on Charlotte Perkins Gilman, who, in the late nineteenth century, left her husband and child. “Her daughter lived to be ninety-three years old and was still bitter,” she said. Ibsen didn’t consider “A Doll’s House” a feminist play, but its impact was seismic. “In England, women said their lives were changed forever,” Showalter said. “Eleanor Marx—Marx’s daughter—learned Norwegian to translate the play.”

Gilligan had helped Hnath fine-tune Nora’s relationship with her children’s nanny, Anne Marie. “It’s a very intense issue within feminism today, where a lot of women are able to pursue the life they want because they hire nannies,” she said. (Ivanka Trump is Exhibit A.) She began making a point about Nathaniel Hawthorne, and became so excited that she knocked her Pinot Noir into her meat loaf. The new play, she continued, “came very close at the end to the transformative feminist vision, which, interestingly enough, is part of nineteenth-century utopian thinking.”

“I am very much a nineteenth-century utopian feminist!” Showalter said.

How did they feel about a man writing “A Doll’s House, Part 2”? “The irony is that the most famous feminist heroine in the theatre, arguably, was written by a man,” Showalter said. “There are aspects of the Nora that we’ve inherited that are filtered through a male consciousness. There just are. But women get a crack at it because they get to perform it.”