Birds of Prey arrives to a fundamentally different environment than its predecessors. Wonder Woman shouldered the weight of being the first female-led superhero film of the modern era; Captain Marvel bore the expectations of being Marvel’s long-delayed foray into female superheroes. But a scant few months after Birds of Prey, audiences will get Black Widow, and after that, Wonder Woman 1984.

Female superheroes haven’t completely “arrived” yet, but they’re definitely arriving. And still, Birds of Prey marks a strange first for the modern era of superheroes: Since the advent of the interconnected superhero cinematic universe with Iron Man, it’s the only female-led superhero film on the books that isn’t a prequel or a period piece.

Captain Marvel was set in the 1990s, while Wonder Woman took place during World War I. Wonder Woman 1984 will still be a period piece that predates almost every other film in its shared universe. This year’s Black Widow is a prequel set just after the events of Captain America: Civil War, sometime around 2016.

What is it about superheroines that makes us relegate them to the past?

They say the past is another country

Wonder Woman, Captain Marvel, and Black Widow — none of them have a jump from the past as part of their origin. Sure, Wonder Woman’s island home is quite different from our own, but thanks to the traditional floating timeline of comic book continuity, these characters’ origin stories have always constantly renewed themselves for the modern era.

One potential answer is that a setting in the past makes confronting sexism easier to do without making audience members question their worldviews. Removing Wonder Woman or Captain Marvel from the present distances the superheroines, and the viewers, from the hurdles of today’s patriarchal systems.

Filmmakers get to present their heroes as go-getting women who stand up to sexist men without implicating the men in the audience, and we all get to pretend that institutional sexism is a thing of the past. This stands in distinct contrast to Wonder Woman and Captain Marvel, who came out of their respective gates as female characters fighting for their place in a man’s world.

Another answer is that in an environment of interconnected storytelling, superheroines are still an afterthought. Their movies don’t push the overall storyline forward, but instead are made to fit into gaps where they won’t affect anyone else. This particularly applies to Captain Marvel and Black Widow.

Captain Marvel hit screens smack in the gap between Avengers: Infinity War and Endgame, when its setting in the past made it instantly clear that it wouldn’t tell us anything new about Thanos or the Snap. And after the title character’s death in Endgame, Black Widow couldn’t be anything other than a prequel. Hopes of a full sub-franchise for the character — as Black Panther, Doctor Strange, and her other contemporaries have gotten — seem slim. Sony’s Spider-Man: Far From Home, the only other MCU-set movie released since Endgame, is likely to have more hints at the future of the franchise than Black Widow.

Both of these answers can change. With more compelling exceptions to the assumption that female-led action movies don’t make money, writers and filmmakers will hopefully feel a little more bold about alienating male executives at the biggest Hollywood studios. And as more superheroines enter the big interconnected cinematic universes (and more superheroes exit for contract reasons), the overall stories of these settings will necessarily have to include them more (hopefully the She-Hulk, Ms. Marvel, and WandaVision Disney Plus series will help this along).

There are things to be gained with superhero period pieces — the power of past iconography, the fantastical fun of a setting that’s abstracted from the modern world — and some superheroes, like Wonder Woman, are uniquely suited to them. But there are also things to be lost. The heroines of Birds of Prey are relatable to an extent their cinematic predecessors can’t quite match, simply because their setting is that much closer to reality. And the strength of their story will build the future of their setting, not just fill in the gaps.