Ian Brennan describes writing the latest season of Monster, about the Lizzie Borden case, as a fever dream.

Brennan, who creates the megahit Netflix true-crime anthology with prolific producer Ryan Murphy, says writing these seasons about infamous serial killers isn’t the challenge — the hard part is deciding who to make the season’s subject. Once they landed on Lizzie, the eight episodes of Monster: The Lizzie Borden Story just flew out of him.

“We were trying to crack the Luigi [Mangione] story,” Brennan reveals to The Hollywood Reporter about selecting their “monster” for the now-streaming season four. But even though the case of the murder of UnitedHealthcare CEO Brian Thompson captured the nation in 2024, Brennan says it was too new and esoteric. It was Murphy who then said he had always wanted to tell the Lizzie Borden story, and Brennan said it instantly clicked to pivot to the woman who was famously put on trial — and acquitted — for the gruesome hatchet murders of her father and stepmother in Fall River, Massachusetts, in 1892. “It feels so obvious like, ‘We should do a woman now.’ But it was much more organic than that,” he says.

Ella Beatty stars as the first female lead in the hit anthology as Borden, alongside Charlie Hunnam (who portrayed Ed Gein in season three’s Monster) as her father Andrew Borden, Rebecca Hall as Lizzie’s stepmother Abby Borden, and Vicky Krieps as the family’s housekeeper, Bridget a.k.a Maggie. Krieps plays double duty, also as Elizabeth Bathory in flashback, and Murphy muse Sarah Paulson appears mid-season in a scene-stealing role as Aileen Wuornos, delivering what Brennan calls a triptych of serial killers to explore female rage and the “cages we put women in and the things they will do to get out of those cages.”

Below, Brennan dives into the fascinating Monster-making process, explaining how he and Murphy take liberties in order to tell fuller stories, why Lizzie Borden was their most sympathetic serial killer yet, and how he and Murphy plan for 10 Monster seasons in total. “There’s a hopper of three [options for next season]. It’s a fairly exhaustive list, but it’s tricky. You’d be surprised at how many subjects we start and then abandon,” he says. “You’re asking people to spend seven or eight or nine or 10 hours getting inside this person’s head. They better be really interesting.”

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Ryan Murphy recently spoke to me about making Monster with you, and he said he loves making the anthology series because, no matter what, it’s controversial and about one thing: Are monsters made, or are they born? When you two go to your Monster ideas board, how many options do you have for a season, and how did you land on Lizzie Borden for season four?

What’s so interesting about the show is that it’s really hard to land on one. The seasons are not hard to write. They’re hard to select. The more you dig into murders and murderers, most murderers are not interesting at all; what they do is just horrible. So it ends up being a taste thing. When Ryan and I start talking about a subject and it gets its own gravity where it just feels like this thing rolling down a hill, we’ll start laughing and smiling. Then we’re like, “Oh, we found it.”

We were trying to crack the Luigi [Mangione] story and it was just laborious and nobody knows it yet. It’s still too new; unknown and esoteric. There’s something not visceral about it. Then Ryan was like, “I’ve always wanted to do Lizzie Borden.” The second he said that, I was like, “Ooh, ooh. I had not thought of this.” And we’d not thought about women, because, proportionally, so few women murder. But even the most cursory discussions had that gravity where I was like, “This is gonna be good. We’re gonna do it.”

It very quickly became that the story we were telling was about female rage. Then we were able to develop this triptych of Elizabeth Bathory, Aileen Wuornos and Lizzie Borden [all three women are featured in the season], which kept the show from seeming like a stuffy, diorama piece by going through these time periods of women who were each aware of the next — Lizzie knew about Elizabeth Bathory, and Aileen Wuornos knew about Lizzie Borden. To have those three stories talk to one another made it feel much more contemporary and of the moment.

We were able to look at rage, female rage, and women who kill as less of an aberration throughout time than actually a throughline and an aspect of our species and existence in society. The cages that we put women in and the things they will do to get out of those cages was really interesting. I’m so glad we did it. Now it feels so obvious like, “We should do a woman now.” But it was much more organic than that. It was only afterwards that it seemed like a natural progression, but we really backed into it and I’m so glad we did.

Ryan Murphy has a deep connection with the Lizzie Borden case; he also told me that he won a choral competition in kindergarten singing the Lizzie Borden rhyme.

That’s amazing. I did not know that.

Being from the Midwest, he said everyone knew the rhyme growing up and he was surprised to learn that wasn’t the case elsewhere. That rhyme was featured in the trailer, and also in the first episode. What was your connection to the Lizzie Borden story?

That’s literally all I knew about it. I didn’t know until researching it that she got away with it. That was totally news to me. I was like, “Well, that’s interesting because if I don’t know this, probably most people don’t.” There are very few historical things like that where you can spring that on an audience. At a certain point, you just have to pick. You do as much research as you can, and then you’re like, “Okay, what do I think about this?” And I’m like, “Well, she definitely did it. Like, of course she did it.” And it’s so fascinating that it didn’t even go to trial. It was a hearing, and they [the men of the jury] actually pretended they were deliberating for another 10 minutes because otherwise it was going to seem like they didn’t deliberate at all. But they didn’t think a woman could do that at all, which is so, so wild to me. But she was very much a blank slate in my mind. I didn’t know the first thing about her.

Is that why you open the show with the murder, to make it clear that the show believes she did it?

Yes, that it wasn’t going to be “did she or didn’t she” do it. I guess it’s similar to what we did with the Menendez brothers [in Monsters: The Lyle and Erik Menendez Story], where you need to see [the murders] first and then go back. Also, in the world of streaming, the more you can frontload, you’re always encouraged to do so.

That opening murder scene has a specific tone to it. I would say a sense of humor about it. How does that capture the tone of the season?

With everything I write, humor kind of runs through a lot of it. I have a very dark sense of humor. But anytime you’re dealing with an environment that’s super repressed, whether it’s high school or the Victorian era, anytime there are things that can’t be done and can’t be said, I find those situations really ripe for irony and that they have a lot of irony baked into them.

The American Victorian era was super repressed, almost like fetishized repression. That was always there. People are always saying one thing and doing another. So we knew very early on that it was going to be a fun story to tell, because she is so enigmatic. Lizzie is a curious person who was underestimated. People thought she was just dumb and that is super fun and funny for me to write to.

It’s clear who the monsters are in the early episodes: her dad, Andrew Borden, and stepmom, Abby Borden, played by Charlie Hunnam and Rebecca Hall, respectively. How much information was available to you in the research and how many liberties did you take? For example, did Andrew Borden chop off the legs of the deceased so he could fit them into his caskets?

I think that is true, although I have to check. It was a similar thing with Ed Gein [season three of Monster] where the further you go back in the past, the more elliptical the story becomes. You’re forced to make decisions, which then allows you to take liberties because you have to fill in the story. That can be seen in one of two ways, that we’re taking liberty with the story, but you’re also trying to fill in the story. You try to fill in gaps to tell a fuller, more true story, if that makes sense.

For instance, with Ed Gein [who was played by Charlie Hunnam], there were very few known facts. There were about 10 or 12 things you could definitively say about him. And if that story just told those 12 facts, that in of itself is taking liberties because you’re telling a story that is full of holes with no connected tissue. That’s no truer a story than taking as much as you can, and then filling in the gap.

I do think that Lizzie killed her father and stepmother. So if that’s the case, then what? What was that house like? You back your way into these characters as much as you can, and hopefully tell a truer or fuller story of what it felt like to be in that house and what it felt like to be her. Compared to if you just told the facts that we are sure of, because they’re so few and far between and covered up. They’re rife with lies, too.

Eric and Lyle Menendez were found guilty, and they told their story, and it’s rife with lies. Whether someone’s found guilty or not, you can never quite get to the real story. So you’re always telling a version of it, whether you like it or not.

Also, in this story, there are no current living members in the Borden family, compared to previous seasons you’ve done.

Exactly. It is similar to Eric and Lyle Menendez where the two people who were never allowed to give their side of the story are the mom and dad. Those two seasons have interesting parallels, which actually did not even occur to me until much later. Someone said that to me, “Doesn’t this seem a lot like the Menendez brothers?” It did not occur to me to draw that conclusion, but that’s absolutely right.

How was the search to find your Lizzie Borden? Was Ella Beatty an obvious choice, or was the search extensive?

It was extensive. It’s weird when you’re like, “Why is this so hard to cast?” We saw great, great, great people, but no one was right. And then it’s that weird thing — I saw the first five seconds of her tape and I was like, “That’s it.” She was her. There’s something super mysterious and really intriguing about the way she looks, and then she’s very, very, very incisive and super bright. So we knew she could handle it, but she’s also just interesting to watch. You can see her thinking, and the character, particularly early on, can verge on being passive and reactive. Ella activated all of that.

You’ll search, search, search, and then someone will just walk into the room and they are so the character, and it was so the case with her. I feel like it’s such a great introduction for her. She did an amazing job with not an easy character at all.

What would you say were the biggest differences in telling a female serial killer story versus the men?

Maybe it’s my own biases, but I understand them better. There’s so much less work to make a female killer sympathetic because you just get where they’re coming from. I’m surprised there’s not more women just flying off (laughs), and that makes it fun because you have to do less work to make the audience feel for them. It’s sort of just there. There’s this pathos and sympathy built in, particularly and surprisingly enough with Aileen Wuornos.

She’s vaguely contemporaneous. There’s footage of her, and I could watch that woman all day long. She has this sort of dirtbag charm, which is also really funny. I felt like, “Man, this woman should have her own talk show. I don’t care how many of her Johns she killed.”

There are likable things about Jeffrey Dahmer, but he’s still Jeffrey Dahmer [season one of Monster]. It’s a much longer walk. It’s a steeper hill to be pushing a stone up, whereas these women are just … I just liked them. I like them more.

Ryan said Sarah Paulson was the only person he could think of to play Aileen Wuornos. Was that just a phone call?

Yeah. I can’t wait until the world sees her performance. It’s so fun and so good.

When does she come in?

Episode four, and then she basically folds up the whole show and puts it in her pocket. It’s so good and so funny. It’s shot so beautifully. It’s a really great episode. We find with this show that around the third or fourth episode, you need to change it up a bit. So when she comes in, it’s just when you’re on the verge of getting ahead of the story. She shows up and completely broadens the story and deepens it. We’re so lucky to have gotten her. She’s one of the greats.

Did the idea of Charlie Hunnam playing Andrew Borden come up while you were making the Ed Gein season with him?

We just didn’t want to say goodbye to him, or Vicky [Krieps]. He was such a joy to work with and we wanted to keep the party going. We were like, “He would be good,” and he was down. And same with Vicky. We just didn’t want her to go back to Germany.

So you gave her two parts? [Note: She plays housekeeper Bridget a.k.a Maggie and Elizabeth Bathory in flashback.]

Yeah. We knew that the Elizabeth Bathory stuff would be shot in Italy at the end of the schedule, but that was Ryan’s idea, and sort of late in the game. He was like, “Well, couldn’t Vicky just do this?” I was like, “Oh, that’s such an inspired idea. I can’t believe we didn’t think of that earlier.” She’s just so great. And strangely, those performances talk to each other in a really interesting way and fill out both characters in a way that was completely unexpected and not on the page at all.

She’s almost narrating herself, since Vicky, as Bridget, tells Lizzie (Beatty) the story of Elizabeth.

Right, so it even makes sense creatively. It was cool.

And Rebecca Hall came from [Murphy series] The Beauty?

Yes. I had not worked with her, but Ryan had. I’m always a bit starstruck when I see her. I’ve been such an admirer for the longest time and she’s the most approachable, warm and normal [person]. I feel like I’ve known her forever. Super, super lovely and fantastically sharp. She’s very, very smart and can really handle dialogue. The Abby character needs to be super sharp and incisive. She’s just the perfect fit.

So how many Monster seasons do you want to do in total, and do you have your next “monster” lined up yet?

We never do. We always switch. It’s always three or four different ones, and we toggle between. There’s a hopper of three things, but Ryan and I both said we want to do 10 of them. It’s a fairly exhaustive list, but it’s tricky. You’d be surprised at how many subjects we start and then abandon, because it’s just not [right]. You can really tell when it’s wrong right away, because you’re asking people to spend seven or eight or nine or 10 hours getting inside this person’s head. They better be really interesting.

That’s always the challenge with this show — finding that. And then once we do, it flies out. It’s a super organic writing process that goes very, very quickly. It’s very easy because you don’t have to invent all that much. You know where it’s going, you know the facts. So you’re more curating episodes, and the writing is effortless.

That’s a very surprising aspect of working in the true crime, how fun and enjoyable it is. Because you sort of know what the story is, you get to be really creative inside those parameters in a way where, if you’re making stuff up from whole cloth, that can actually be much more laborious.

Next up, you have The Watcher season two for Netflix?

Yes. I was just writing that.

What can you tease?

Nothing. I’m being told absolutely nothing. It’s gonna be good, though.

Is there a timeframe for when it will release?

I don’t know yet. Watch this space!

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Monster: The Lizzie Borden Story is now streaming all episodes on Netflix.