Aline Brosh McKenna knows romantic comedies inside and out — which is why she takes so much delight in perverting them completely for Crazy Ex-Girlfriend.

Before McKenna teamed up with Rachel Bloom to co-create the CW’s twisted musical delight of a show, she wrote romantic comedies. She sent plucky heroines into the hellmouth of dating with a determined smile and slyly sharp wit. And even though her scripts occasionally got to draw blood — especially The Devil Wears Prada, her biggest hit to date — it wasn’t until Crazy Ex-Girlfriend that she got to unleash the full range of passion and anger that can make for truly memorable heroines.

Because Rebecca Bunch (Bloom), a whirling dervish of feverish passion and debilitating anxiety, is no heroine — not in the traditional sense, anyway. She spent the series’ first season plotting to win the heart of friendly bro Josh (Vincent Rodriguez III), whom she decides could make her happy, insisting all along in her chirpy theme song that she “has no underlying issues to address.”

In the second season, she parlayed their hookup into not just a real relationship, but an engagement that ended in Josh leaving her at the altar in the finale. Crushed, heartbroken, and more than a little lost, Rebecca vowed revenge — and that’s where we pick up with her in season three, which has her going after a decidedly more Fatal Attraction vibe than the carefree romance she was so desperate to recreate.

So, no, Rebecca isn’t anything like the heroines McKenna used to write, whose problems had to be minimal enough that they could be solved in 120 minutes or less. In fact, McKenna told me, “There’s a joke in the first season where a homeless woman asks Rebecca for money and she says, ‘Oh, I’m sorry, I only have 20s. I got them from working.’ Which I would never, ever, ever, in any rom-com I wrote in my career, be able to do that.”

So when I got the chance to sit down with McKenna back in August at the Television Critics Association summer press tour, I didn’t just want to hash out what’s next for Crazy Ex-Girlfriend; I wanted to talk about why it’s so much fun to subvert the rom-com tropes we’ve long taken for granted. (This interview has been edited and condensed for clarity.)

Caroline Framke

What is particularly exciting for you going into a third season versus setting everything up in the first?

Aline Brosh McKenna

It’s gotten progressively more intense [for Rebecca], psychologically. She’s really now in the phase where, it having not worked out in such a spectacular way, her feelings about that are just as powerful as her feelings of love for him were. So in some ways, she’s just as obsessed as ever.

Caroline Framke

There’s always this push and pull between whether or not it’s more about him, or more about her—

Aline Brosh McKenna

The obsession? Oh, it’s a thousand percent about her. It has absolutely nothing to do with him. He could be a house plant.

Caroline Framke

Was there a moment early on when you thought you found the right tone for this show?

Aline Brosh McKenna

What you have to picture is two women just talking about it incessantly. Rachel and I met in June, wrote the pilot over that summer, and we’d talk for hours, and hours, and hours. I have notes from the first couple times we met, and they’re very accurate to what the show is. It just felt like there were all these things we were bursting to talk about.

And I think if you look at Rachel’s previous work and mine, you can see that it’s sort of a blend of the sketch stuff she was doing and the more traditional storytelling stuff that I was doing. I had done rom-coms, though I wasn’t doing as many when we were working together, I was doing things with a more dramatic bent like We Bought a Zoo. So I think it really is a blend of [my] longer character arc stuff with [her] more madcap comedy.

Rachel is still the funniest person that I know, and the person that just drops me to the ground laughing every day … she also has no vanity. For an actor, Rachel isn’t in this endeavor to look cute. That’s not at all what she’s doing. It’s wonderful to work with someone who’s as beautiful as she is and cares as little about it. That’s why I often think of Lucille Ball, Madeline Kahn, Julia Louis Dreyfus, women who are more “traditionally pretty,” but who are willing to send that up. And that’s Rachel, always.

Caroline Framke

Being someone who is really well-versed in rom-coms, I’d love to go through some of the tropes that Crazy Ex ... well, totally fucks with. Like with Josh as “the nice guy.”

Aline Brosh McKenna

It’s funny, no one’s really asked me about that, particularly with the men … having written rom-coms, Josh is like, what Ed Burns is in 27 Dresses, and Greg [former castmember Santino Fontana] is like what James Marsden is. That triangle — I mean, ’twas ever thus, from Randolph Scott and Cary Grant, to Jimmy Stewart and Cary Grant.

We try to get under those tropes. That kind of talking mannequin that is Josh, he’s also kind of a coward, he doesn’t know who he is. [Crazy Ex] was an opportunity to take those tropes that I had been writing about and explore them in a different way. Now Nathaniel [current castmember Scott Michael Foster] is yet another trope, which is the deeply damaged, very attractive asshole. So in the same way that Rebecca’s the trope of the kooky, slightly madcap girl that comes in and “what’s up doc?”s your whole life, the men are also tropes.

What we try to do is say, “what’s inside that trope?” Paula [Donna Lynne Champlain] is the Rosie O’Donnell, Judy Greer best friend. Well, what’s that person really about? What’s their life really about? Darryl [Pete Gardner] is the goofy boss. What’s his point of view really about?

That’s really what we’re trying to do, is show that these are real people falling into established patterns that are received from the culture. Rebecca receives all her messages from popular culture. And I think to a certain extent, we’re all kind of acting out these love scripts that have been written by other people.

Caroline Framke

Rebecca’s trying so desperately to cast herself as the lead heroine, which you see all the time in rom-coms. I recently rewatched How to Lose a Guy in 10 Days — which I used to watch all the time — and Kate Hudson’s best friend is Kathryn Hahn’s character, who’s just a total mess who’s getting broken up with every day.

Aline Brosh McKenna

That’s exactly it. The very first shot of our pilot is a beautiful blonde girl singing South Pacific, and then you move past her to the awkward girl in the back who’s painted freckles on her face and is singing out of tune. That’s Rebecca Bunch. She very desperately wants to be the kind of effortless, yellow silk bias-cut gown Kate Hudson character. That’s who she wants to be.

Caroline Framke

You talked at the [TCA] panel about how you’d have to “protect the lead” in your movies. What has been the most exciting part about being able to unleash Rebecca as a rom-com heroine in a way that you couldn’t before?

Aline Brosh McKenna

There’s a joke in the first season, where a homeless woman asks Rebecca for money and she says, “Oh, I’m sorry, I only have 20s. I got them from working.” Which I would never, ever, ever, in any rom-com I wrote in my career, be able to do that.

The reason we’re allowed to do that is because Rachel Bloom is our lead and she’s a human beam of sunshine and joy and love and sweetness, but Rebecca is kind of a jerk. She’s very self-centered and doesn’t really listen to other people, and there are underlying reasons for that. But a lot of her behavior is very selfish and, you know, not so great.

Caroline Framke

You and Rachel have talked a lot about how Rebecca is something of an antihero. Is striking some kind of balance still something you guys talk about in terms of trying to keep her sympathetic?

Aline Brosh McKenna

I guess we do see her as an antihero. Rachel used to say “bubbly Walter White.” But I just kind of see her as a person who has struggles and difficulties. We all do things we’re not proud of, we all do things where we wake up and ask, “Why did I do that?!” Especially in our love lives … you know, when I was stalking boys, there were no cell phones, so I was just stalking people with landlines. It was awful! Awful. The phone would ring and ring and ring, and then there’s answering machines. So I’m glad I didn’t have to date in the age of technology. It would’ve been not pretty for the guys I was in love with.

Caroline Framke

Rebecca’s mental health does come up in significant ways throughout the show, but right before the season two finale pushes her over the edge, it explicitly reveals a very serious time in her life when she was institutionalized.

Aline Brosh McKenna

We’re going to explore that tremendously in this season. She’s going to get a diagnosis, and a new course of treatment. We’re really exploring, in a real way, what’s underlying Rebecca’s issues.

Caroline Framke

Is that something you felt you had to do?

Aline Brosh McKenna

Always. We were always going to do that with the series, because once you call someone crazy — which is a meaningless term — [you have to answer] what does that mean. What is actually plaguing her? And it’s from the point of view not from outside pointing to her, but from the inside. She’s not a happy person. She’s in a lot of pain.

Caroline Framke

It’s always so frustrating, but so real, to watch her get so, so close to acknowledging it.

Aline Brosh McKenna

Yes. But as things become more emotionally intense this year, there are fewer places for her to hide.

The third season of Crazy Ex-Girlfriend premieres October 12 at 8 pm Eastern on the CW. The first two seasons are currently available to stream on Netflix.