With Avengers: Endgame in the rearview mirror, it's time to contemplate what's next for some of its biggest stars.

Unfortunately, the final entry in the Infinity Saga forced fans to say goodbye to some of their favorite characters, at least in the films' current timeline.

Warning: This article contains major spoilers for Avengers: Endgame.

Scarlett Johansson's daring Black Widow was among them, having traded her life for the greater good of the universe. When Black Widow and Hawkeye reach Vormir as part of the movie's time-traveling narrative in 2014, they're met with the Red Skull, who tells them that they must make a sacrifice if they want to collect the Soul Stone. You can probably see where things are going from there.

As such, fans have been mourning the loss of Natasha Romanoff ever since the movie's credits rolled. Thankfully, it's not the end of her character, at least in terms of seeing her on the big screen. There's still a solo movie in the cards for Romanoff, which is great news for anyone still bummed by her fate. But when it comes to a solo Black Widow movie, what do some of her biggest fans want to see out of it?

What do we know so far?

First, let's recap some important details. The long-delayed Black Widow solo movie will reportedly begin filming in June, though nothing official has been announced just yet. In early April, Stranger Things star David Harbour and The Favourite's Rachel Weisz were tapped for roles in the upcoming flick, according to theHollywood Reporter. It isn't clear who either actor is set to play, but we do know they'd be joining Johansson and Lady Macbeth's Florence Pugh.

What could the movie explore, though? We're not sure at this point. First of all, it would undoubtedly have to be set in the past, given Black Widow's ultimate fate. Her death was enough to spark controversy, in fact, as she was the only woman in the Avengers' original lineup and the only woman superhero in the entirety of the franchise before 2014's Guardians of the Galaxy. Before that, she was continually underused. Time and time again, she was offered second-tier story lines that her male counterparts didn't have to worry about.

Marvel Studios head Kevin Feige first spoke a solo Black Widow movie into existence in 2010, nine years before the first female-led MCU film Captain Marvel arrived in theaters. Needless to say, it's been a long time coming. But fans are doggedly determined to see her get the moment in the spotlight she so richly deserves, one way or another.

Fans want an espionage-focused action film

A spy-focused film with plenty of moments for Black Widow to shine seems to be No. 1 on some diehards' laundry list of solo movie must-haves, and for good reason. It's time to see her come into her own, especially after spending so much time as a vehicle for other Avengers' stories. The character has a rich history, and this seems like the best course of action for the film, which already has a script ready and waiting.

"I would love to see Natasha in her Iron Man 2-era persona, where she's a total badass, working undercover and infiltrating organizations, spying, being sharp and smart and subversive and strategic with her tactics, and also kicking ass while doing it," said Arc System Works's Karrie Shirou.

"In the recent Avengers movies, the threats have become bigger and badder, and the usefulness of Black Widow — and more physical, human strength-type characters like Hawkeye — have been really diminished in importance," she continued. "I want to see her doing things that only Black Widow can do, to establish why she was someone the Avengers needed as more than a gopher."

And then there's Natasha's own bloody backstory. "I see an espionage centered prequel that focuses on Black Widow being an assassin, going undercover, and other various aspects of being a spy. Essentially her earning the 'red in her ledger' but also the eventual journey away from that life that leads her to being who she was in the start of Iron Man," said Joshua LeMay, Black Widow fan and host of the A Trouble with Words podcast.

"Fun but dark in tone with plenty of action scenes covering everything from physical combat, gunplay, interrogations and chases. Also, it would be interesting to see how she handles friendships and relationships in general at that time [in her life]," LeMay continued.

Early details about the film indicate that it'll be an "internationally-set story centering on Natasha Romanoff, a spy and assassin who grew up being trained by the KGB before breaking from their grasp and becoming an agent of SHIELD and an Avenger." So, the movie will likely end up meeting those fan expectations, at least in this respect.

Black Widow fans want her to be in the spotlight

For a Black Widow movie to work, fans point out that she can't just fade into the background of her own story, which is what's tended to happen even when she's played a major role in the Avengers films.

"Black Widow has always kind of faded into the background in the movies. She's been this sort of ancillary character," said longtime Black Widow fan Katie Sims. "I want her to have more agency, better lines, snarkier comebacks. I want her to be the center of attention for once. She deserves more." More screen time is certainly a good thing, given that the plots for each Avengers flick were divided up between so many heroes she barely got any face time.

"She needs to be crux of the movie — not just given another mission by S.H.I.E.L.D. to carry out James Bond-style, where the characters are almost interchangeable," shared Shirou. "I'd also like to see her free of the trappings of the Avengers — no lingering Hulk romance, or her trying to get back to her friends if it's a post-Endgame movie."

It may seem like a no-brainer that Black Widow should be the "star" of her own movie, but it's not like that concern is completely unearned. The character could still be met with the same pitfalls we saw with Captain Marvel and Wonder Woman, where men still played major roles in women's stories.

"I'm cautious about how they handle the 'girl power' aspect of the movie," explained Shirou. "Clearly, this is the hot thing in Hollywood right now, but we've already seen the stories of women overcoming male oppression with Captain Marvel and naive women learning about the world through a male guide with Wonder Woman. I want to see someone capable, smart on her own accord, and not needing to form a team of women to fight together. I want to see her in full, glorious power in her own right."

Fans want to know more about Black Widow, but not too much

Part of Black Widow's passionate fanbase is very much interested in learning about the rest of Natasha's life beyond her time with the Avengers. In offering up this kind of content, a solo film could add an exciting new dimension to the character that's been sorely needed ever since we had the pleasure of meeting her.

"I'd love to hear the story behind the relationship between Hawkeye and Black Widow, how Nat ended up at S.H.I.E.L.D., and of course, what happened in Budapest. I gotta know about Budapest," said Marvel fan Kaitlyn Stewart.

The aforementioned "Budapest" refers to a past mission she and Hawkeye reference in 2012's Avengers. "Just like Budapest all over again," Clint tells Natasha while fighting off Chitauri troupes. "You and I remember Budapest very differently," she replies. Fans have been curious ever since.

And then there are fans who are just more curious about Natasha's life in general, her likes and dislikes, while still getting some things under wraps. "I want to see the film strike a balance between offering details about her life," Sierra Edds said, "but I don't want to be flooded with too much." It makes sense — Natasha is known for her secrecy.

"The constant struggle between the guilt from her past life and her desire for vindication makes for a great emotional experience," continued Edds. "The point of solo movies is to make you feel more connected and closer to the character. As much as I like a mysterious backstory, I love some interesting and juicy details, and I think it would be most appropriate for the character to keep some of her secrets and dignity while still satisfying [fans'] curiosity."

Sims echoed the sentiment, noting that she doesn't want the movie to be an "expository buffet" with needless plot details thrown in as "fluff." With so many comic book appearances to draw from, there's plenty of material the movie could explore without resorting to anything too contrived.