Lizzie Borden died in 1927. Aileen Wuornos wasn't born until 1956. So when Sarah Paulson turns up as Wuornos in episode four of Netflix's Monster: The Lizzie Borden Story, it isn't because the two women ever crossed paths. It's a deliberate swerve by the show, and both showrunner Ian Brennan and lead Ella Beatty have now laid out why.

The fourth season of Ryan Murphy's Monster anthology, after runs on Jeffrey Dahmer, Ed Gein and the Menendez brothers, centres on Borden (played by Beatty), acquitted in 1892 of hacking her parents to death with an axe. Wuornos, the Florida sex worker who killed seven men between 1989 and 1990, shows up mid-season reading a book about Borden, soliciting and killing a client, and eventually visiting the Borden house with her girlfriend before her death.

"The show is exploring a legacy of female rage and reaction to the set of circumstances that they are presented with," Beatty told Netflix Tudum, according to Just Jared. She said the Wuornos thread also feeds "that question and that exploration of why women kill."

Brennan, speaking to Collider, put it in blunter terms. "When Aileen Wuornos enters the picture, it's just magnificent," he said. "It felt important to us to keep drawing the line to say that this isn't just a historical thing — this is something that is happening today." He went further, tying the show's Victorian repression to present-day politics: "Women only had the vote in 1920, and there are still people, half the internet. Who would like to go back to that. It's a myth to think that's somehow in our past."

The punk soundtrack, heavy on female acts from the '70s and '80s, does similar work, Brennan told Collider, stopping the season from settling into a stuffy period piece.

It's not the first time Murphy's Monster universe has bent the timeline for a thematic crossover. The Dahmer season brought in John Wayne Gacy despite the two killers never actually meeting. This time the device stretches further, running from Elizabeth Báthory in the deep past through Borden to Wuornos in 1989-90.

Brennan also told Collider he deliberately avoided prior Borden adaptations while researching, working instead from primary sources, and came away convinced she did it despite the acquittal. "She was a young woman who was in a cage her whole life," he said. "The more I learned about her, the more I sort of felt for her."

All episodes of Monster: The Lizzie Borden Story are streaming on Netflix now. Whether a fifth season picks another female killer, or returns to men, is the one thing Brennan hasn't said.