‘Crazy Ex-Girlfriend’ just as crazy entering its final season

The final season of “Crazy Ex-Girlfriend” will, at times, feel like a relapse rather than a recovery for its central character Rebecca Bunch.

“Believe me, a lot of the season revolves around backsliding,” says series co-creator Aline Brosh McKenna. “It’s the same as with a [mental health] diagnosis. Just because you know that you have certain tendencies, it doesn’t mean that all of a sudden you become a perfect person who doesn’t make mistakes.”

The love-crazed lawyer played by Rachel Bloom struggled to find her footing while moving to a new city and learning how to be a (well, not so great) friend. After three years of watching her attempt to come to terms with her own relationship and mental health struggles, it’s near nearly impossible to wrap up her complex life without straying from the core of the character we’ve come to know so well.

When we head back to West Covina, California, Rebecca will be crossing over into “Orange Is the New Black” territory, trading in her business suits for an orange jumpsuit. She pled guilty to attempted second-degree murder after pushing stalker Trent (Paul Welsh) from a balcony, remember?

“What she is trying to do in this season is figure out how to take responsibility,” McKenna says. “Deciding she wants to be in prison is a misguided attempt to make peace with everything at one time.

“It’s typical Rebecca Bunch fashion. It’s a grand gesture and somewhat doomed to fail.”

Ahead of the Friday premiere, McKenna delves into why it’s time for the CW series to end and what fans can expect from the appropriately crazy goodbye. 

You’ve been open from the start that “Crazy Ex” was only supposed to exist in four installments. Did you map out where the series would end years ago?

Rachel and I always wanted it to be a closed ending. One of the opinions we shared when we met was that some shows kind of evolved past their premise, which can be fun, but it’s not really what we wanted to do. We wanted to take a tight version of this premise and do it justice. And so that’s what we’ve always set out to do. It’s also such a difficult show to produce, and exhausting for Rachel. It’s not like we had everything, every detail of it, worked out in advance, but we had the general kind of movements of her evolution mapped out.

It seems that prevented the series from falling into the trap of overstaying its welcome.

Luckily, the upside of not being very highly rated is it’s not like we had a corporate imperative to keep going. I mean, we’re not sort of a linchpin in anyone’s corporate well being.

Rebecca has been trying to take responsibility for her actions for a few seasons now. How will we see that wrap up in the finale?

[Entering prison] is the beginning of the journey of taking responsibility. I think she is an enormously privileged character by virtue of her background, education and her skin color. A lot of these are things she hasn’t thought about. She’s been distracting herself with a singular focus of her love life. This is a journey toward understanding what roles she occupies in the world. One of the joys of writing her actually is that she’s rather self-absorbed.

You can’t really wrap this up easily for Rachel without it straying from who she is as a character. Do you think fans will be pleased with the ending you’ve mapped out for her?

I hope so. I mean, they are very smart and they always seem to understand what we’re doing. I’m constantly amazed at how insightful this kin is … you know, you really can’t write a show with that in mind. You have to write the show with your own ends and goals and aesthetic in mind and then you hope people like it. But that can’t be the primary reason. Otherwise, all the characters would end up together and happy.

I’m picturing a massive wrap-up musical number.

You are right in wanting and hoping for that. We will see if we have any money left by the time we get to the end. So, I’m hoping that we do. 

On TV: "Crazy Ex-Girlfriend" returns Friday at 9 p.m. on the CW. You can catch up now on Netflix.