Hulk (Mark Ruffalo) and Black Widow (Scarlett Johansson) in “Avengers: Age of Ultron” (Marvel/Walt Disney Studios)

This post discusses the plot of “Avengers: Age of Ultron.”

Joss Whedon, the auteur who rose from indie television sensation “Buffy the Vampire Slayer” to stewardship of some of the most important movies in Marvel’s Cinematic Universe, has seemed more than a little burned out lately. And yesterday, he quit Twitter. The reasons for his departure are as yet unknown, but some speculation has centered around criticism Whedon received for his handling of the character Natasha Romanoff (Scarlett Johansson), a former assassin and the lone woman in the Avengers lineup.

Indeed, a feminist critique of Natasha, motivated as much by Marvel’s failure to deliver merchandise and a stand-alone movie around the character as by anything in the script, crescendoed as Whedon’s latest film, “Avengers: Age of Ultron” arrived in theaters this weekend. I’m sympathetic to many of the larger complaints, but I find the criticisms of Natasha’s story lines baffling. “Age of Ultron” has its failings, including choppy editing that make Whedon’s character-driven action sequences less coherent. But it’s hard to think of many movies or television shows that spend more time exploring what it means to be both a woman and a action hero. It’s a worthy entry in the oeuvre that made Whedon a feminist icon in the first place.

Ultron returns to cause even more trouble for the heroes in another trailer for Marvel's "Avengers: Age of Ultron." (Walt Disney Pictures)

One of the great delights of “Avengers: Age of Ultron” is the way the movie pokes at our assumptions about what’s happening when a man and a woman appear close on-screen. It was clear that there was something more than mere camaraderie between Natasha and Clint Barton (Jeremy Renner) in “The Avengers.” When she went to visit Loki (Tom Hiddleston) in an attempt to figure out what he’d done to the brainwashed Barton, the Asgardian trickster jumped to the logical conclusion: “Is this love, Agent Romanoff?” “Love is for children,” Natasha told him coldly. “I owe him a debt.”

It was a response that left room for her to be in denial, but “Avengers: Age of Ultron” revealed something rather more subversive, at least by the standards of contemporary filmmaking: Natasha and Clint are what they say they are, not soulmates in denial but the best of friends. And Natasha’s close to Clint’s wife, Laura (Linda Cardellini), too: “How’s little Natasha?” she asks Laura when they arrive at Clint’s house. “Actually, he’s Nathaniel,” Laura confesses. “Traitor,” Natasha whispers to the baby. In a few efficient lines, Whedon’s sketched in a warmer side of Natasha’s personality. It’s not that it didn’t exist before; it’s just that, until the trip to the Bartons’ farm, she wasn’t around the people who deserved to see it.

Later, as she and Clint weave through the ruins of Sokovia, they diffuse their nerves by talking about Clint’s latest idea for a home renovation, a plan to turn his dining room into a workspace for Laura. “You guys always eat in the kitchen anyway,” Natasha tells him, cool as the world is falling away beneath them. There’s a subtle but profound intimacy to the exchange: It’s proof of how well they know each other, how much comfort they take from each other, how well Natasha is integrated into Clint and Laura’s lives.

The burgeoning relationship between Natasha and Bruce Banner (Mark Ruffalo) is spikier, not least because they’re the inverse of one of Whedon’s most famous romantic pairings: Buffy (Sarah Michelle Gellar) and Angel (David Boreanaz) from “Buffy the Vampire Slayer.” In Whedon’s still-radical television show, the titular vampire slayer and the reformed vampire slept together, only for the moment of perfect happiness that followed to strip Angel of his soul, turning him back into the monster he’d worked so hard to exorcise. Buffy and her friends work to contain Angelus by any means necessary: witchcraft to restore his soul, a stake when that partition against Angel’s worst self doesn’t come up fast enough.

Natasha, on the other hand, would rather bring out her lover’s dark side than contain it. “I adore you,” she tells Bruce, after they share their first kiss and shortly before she pushes him off a chunk of city that’s headed rapidly skyward. “But I need the other guy.” She trusts the Hulk — at least around her — even if Bruce doesn’t. The moral monster in her is drawn to the literal monster in him. They don’t need to partition off those parts of themselves or destroy their most dangerous impulses and abilities: they can rechannel them.

They aren’t there yet, though, and there’s a frisson of danger to Bruce and Natasha’s interactions throughout “Age of Ultron.” In the aftermath of the movie’s first battle, a choppy, cacophonous affair, the real tension builds when Natasha approaches the grumbling Hulk in a snowy glade. The exchange that follows has the air of a magical rite that hasn’t quite gone through beta testing: an incantation, a touching of hands, Natasha’s fingers skimming lightly over the Hulk’s impregnable skin. Beauty’s soothing of the Beast has never been quite so sensual, and it’s never required so much courage from Beauty.

But back at Stark Tower with a party under way, the equation is reversed. Natasha, equally at home mixing drinks behind a bar and firing off shots while charging up a staircase in heels, is the intimidating figure, while Bruce, shaggy in his professorial blazer and out of place among the revelry, is at a loss: He doesn’t have Thor’s (Chris Hemsworth) talent for revelry, War Machine’s (Don Cheadle) battle stories, or Steve Rogers’s (Chris Evans) camaraderie with the World War II veterans who have been invited to the festivities. To a certain extent, that isolation is part of the point: The fewer people Bruce is close to, the fewer he can really hurt and betray. Natasha’s flirtation challenges the gulf between him and others that Bruce uses as a moat. What Steve identifies as a potential win for Bruce and Natasha feels like a terrible risk for Bruce.

And they find themselves on equal footing in Clint and Laura’s house, when they broach a deeper reason Bruce thinks they might be incompatible, beyond his tendency to turn green and smash-y: his infertility, a trait they turn out to share thanks to the “graduation ceremony” at the facility where Natasha was trained to be an assassin, in which graduates are sterilized so they won’t prioritize any potential children over their missions.

The scene has sparked a certain amount of feminist ire: “Did we really need Natasha to have a mini-breakdown over the fact that she can’t have children?” Sara Stewart wrote in Women and Hollywood. “Haven’t we gotten to a point where the one lonely female superhero in our current landscape can just pursue the business of avenging without having to bemoan not being a mother?”

Marvel’s critics aren’t wrong that the franchise has been oddly slow to put women at the center of its movies. But this line of criticism, or Jen Yamato’s contention that the films have treated Black Widow like nothing more than a cheap temptress, seem to me to miss the mark.

Natasha’s not a super-powerful woman suddenly brought low by a reckoning with her biological clock or the fact that putting the hurt on intergalactic baddies led her to put off developing a personal life. She’s a hero reckoning with what it means to be both female and merely human in a testosterone-heavy, super-powered environment. Natasha may not be able to have her own children, but she’s built a family of her own — in a late shot in the movie, we see her waving at baby Nathaniel via video chat. And if most men are easily and lazily dazzled by her most readily apparent qualities, she’ll find one who responds to the darkness in her.

In fact, Natasha reminds me of no one so much as the late humorist Veronica Geng, at least the way Jennifer Senior described Geng in a New York Magazine profile. “Seduction thrilled her. There were actors, rock stars, writers, even a professional baseball player. She categorically rejected the notion of promiscuity and said she had no patience for sexual jealousy,” Senior wrote. “But Geng was also a woman’s woman — someone who burrowed into her work, kept secrets, shopped with glee, cooked with flair, and tenderly looked after her friends’ kids.”

And ultimately that’s a great deal of what I want from my female action heroes: that they not be required to take off their femininity when they suit up for battle, and that they not be required to leave it hanging in the closet when they return from the wars. Certainly, there are some female characters for whom violence may be straightforward and have few other implications for their senses of self. But isn’t the whole point of having women as well as men be superheroes and swordfighters that they bring a new range of perspectives to our experiences of these very old stories?

“Game of Thrones” has done a beautiful job of addressing this issue with the female warrior Brienne of Tarth (the routinely outstanding Gwendoline Christie), who has both been rejected by and rejected her country’s standard for femininity but still longs for the love and intimacy she’s assumed are unavailable to her. Natasha comes from a different perspective: Sex and seduction are easy for her, but she doesn’t mistake their instrumental uses for intimacy, love or family.

The tragedy of Natasha’s character isn’t that she’s been felled from her mission by her love for babies. It’s that her mentor (Julie Delpy) took something away from Natasha that didn’t have to be removed for her to be a hero. She could have been a lover and mother and friend and fighter all at once. That Natasha’s male compatriots aren’t asked to reconcile supposedly disparate parts of their personalities is their good fortune. That Natasha works so hard to do so is the measure of her heroism.