"She knows there's a good person inside of Phil, and she's determined to bring out the best person he can be," the actress tells THR.

Behind every great man, there is an equally great woman — and, it appears, behind the slovenly and dejected last man on earth, there is an equally neurotic and optimistic last woman.

During new Fox comedy Last Man on Earth’s series premiere Sunday, viewers were surprised by the show’s first big reveal — while Will Forte’s Phil Miller was still technically the last man on Earth, he was not alone.

After a futile search for fellow survivors of a mysterious deadly plague that wiped out civilization, Phil Miller has finally reached the end of his rope. Despondent, devoid of any hope and committed to ending it all, Phil is just about to crash his speeding truck into a rock formation when sees it — smoke from a fire and proof that someone else is out there.

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Enter Flight of the Conchords' Kristen Schaal, whose offbeat and rules-obsessed Carol Pilbasian immediately clashes with Phil’s more hedonistic tendencies. Not quite the company he had hoped or expected, Phil now finds himself (reluctantly) engaged and headed for marriage in hopes of finally getting some restoring the population.

So what’s next for the last two people on Earth? The Hollywood Reporter caught up with Schaal to talk keeping secrets, her “loveable” character, and where these two opposites go from here.

So the big twist of the premiere was that Phil Miller was the last man but not actually the last person on Earth. What was it like trying to keep that secret for so long?

Oh, it was really right up my alley. That’s sort of how I would always prefer to do things. (Laughs.) It was fun go to a job that nobody knew about, and I liked keeping the surprise. It was great.

What was the reaction like when people found out? Were people shocked?

Yeah, a few friends, were like, "Whoa! I didn’t know you were in this! I had no idea you were in this!" They were very excited.

So far, we’ve primarily seen this post-virus world through the eyes of Phil. How will we begin to see Carol’s point of view shine through? Where is she coming from in all of this?

You’ll get to know and love Carol more as the series continues. She is has a real sweetness to her — like a truly authentic sweet spot — and, like she said in the second episode, she knows there’s a good person inside of Phil and she’s determined to bring out the best person he can be. There’s something so endearing about the integrity of that. On one hand, it could seem kind of controlling, but on the other hand, she’s basically his savior because he's at the end of his rope. Her mission is totally sincere. Whether or not it’s misguided, it’s coming from a good place.

Carol seems to be very strict with maintaining certain rules for living. How much of that controlling nature is part of her actual personality? Is it inherent to who she is or is it more of just her way of coping with this insane world?

Oh, yeah. It's part of her personality. She was always a stickler for the rules, but I think because of the circumstances she’s definitely taken it up to the extreme. It's a lot like what Will did with Phil on the other side of the spectrum — with the grammar and the stop signs and making sure everything is as it should be even in a completely order-less world. Something fascinating, too, is that now that she's found another person, there's a real power play that happens. Who gets to call the shots? It’s kind of awesome to see that delicate dance going back and forth. Who gets to call the shots in a world that is — almost — completely all your own? Carol is really fighting for control.I think she didn’t have a whole lot of control in the old world, and she’s going to make sure she gets it now.

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As Phil notes in the episode, such an obsession with rules that no longer matter seems almost silly. Were you ever afraid that the audience may be turned off by that part of the character?

I always play really offbeat characters, and I sometimes worry that they're likeable even if they're weird. Some characters — like Mel from Flight of the Conchords — you look at and are like, "Ugh, this woman is so up in their business and such a pain." I look at her and think, "I’m going to make people love her. I’m going to find a way to love her no matter what." With those characters that are quirky and offbeat, there’s something about them that’s really even more vulnerable and that ‘s really fun to play with.

At the end of the premiere, Carol proposes that the two of them get married, to which — out of almost sheer desperation — Phil agrees. Being so obsessed with rules, how will Carol reconcile the fact that they don’t have the necessary officiant or witnesses?

Part what happens next is about how Carol organizes the wedding, and I’m pretty sure Carol is a justice of the peace.

With Phil and Carol at such opposite ends of the spectrum in their reactions to their world, will we see those two ever find a middle ground?

Oh, absolutely. These two characters are going to engage in a very entertaining dance — a very unusual dance — that I’m very excited about.

We saw small little flashes back into the life before the virus. Will we see more flashbacks in upcoming episodes? Will we perhaps see Carol before the virus?

We might a few flashbacks, but no, there won’t be any Carol flashbacks, unfortunately. Only in your dreams, your own personal dreams. (Laughs.)

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But we will learn more about the virus? Will the audience see what life was like living through this obviously horrific experience or will the show simply keep moving forward in this era after the virus?

There will be a couple conversations here and there as the series goes on and maybe tiny hints drop, but it won’t be the main focus of what’s happening.

Having ruled out flashbacks with Carol, will we perhaps see some dream or fantasies? Perhaps with some of the other cast additions who have been announced like January Jones, Mel Rodriguez or Cleopatra Coleman?

Maybe, you never know. These new cast members — they could be Phil and Carol’s offspring for all we know, just years in the future.

Speaking of the future, the show takes place in the year 2021. Will we see any sort of references to pop culture or other things from the years between now and then? How much is that future different from what we know now (aside from, you know, a virus wiping out the entire population)?

That's actually an interesting point I was chatting about with Will. I think what’s cool about the series taking place in 2021 is that whatever is happening in our culture now kind of gets frozen there — because once the virus happened and it started destroying our entire world, there wasn’t an opportunity to make new culture. So, the cultural references are all from now. There are no new inventions or pop stars or television shows or movies that have happened between now and the time you see Phil and Carol because people were just in the midst of a horrific battle for survival.

With such an uneasy partnership slowly but steadily developing between Carol and Phil, what’s the one thing viewers can expect between the two of them in this upcoming episode?

Let’s just say that Phil still stinks. It’s not a great tease, but it’s true. (Laughs.)

Last Man on Earth airs Sundays at 9:30 p.m. on Fox. Like the premiere? Curious to see how this all plays out? Sound off in the comments below.