Things haven't gotten too crazy for Rob Thomas -- yet.

Tonight, The CW airs the first season finale of the "Veronica Mars" creator's adaptation of Chris Roberson and Mike Allred's Vertigo comic "iZombie," and when its over, things will be getting crazy in a number of ways. For one, the show is about to begin production on its second year. "We're back in on Season 2 right now, but it's just the writers," the executive producer told CBR News. "We have about six weeks before the show actually starts shooting. So while we are busy, it's not the insanity that will start in a few weeks when we're both shooting and writing."

But from a fan perspective, this week's episode draws together a number of storylines as the brain-eating mythology of the show's zombie idea culminates in a final confrontation between Liv and Blaine. CBR spoke with Thomas about how the series has evolved over Season 1, why the show will never be "The Walking Dead" or "Game of Thrones," and what viewers can expect in terms of major payoffs from "iZombie's" freshman finish.

CBR News: Last week's episode took a turn towards horror in a way that we haven't seen before, even though this is a zombie show. That tone, and the dire, serious nature of Liv's existence seems to have built as the episodes have gone along. Was that by design?

Rob Thomas: There are probably two things going on at once there. One is that just over the course of the season, we came to realize to some extent that the most fun of the show revolves around the zombie mythology. I feel like we kept stealing pages from our A-story to give to the mythology. So, the case of the week would suddenly get five less pages in the script, and those would be devoted to more zombie action -- or at least the mythology. And then for two, I think almost any show when you get closer to the end of a season you start to lean on the ongoing stories to build more to that climax. That's just the natural rhythm of the show.

We are aware, though, that we can't try to out Walking Dead "The Walking Dead." They've got a whole different set of broadcast standards and practices and an entirely different budget. So we have to choose our moments with the violence and gore and zombie makeup. I don't think we could pull it off every week financially, and I'm really not sure how much that would be playing to our strengths. We kind of have to rely on being witty when we can't afford more than four zombies at a time, you know? [Laughter]

So there will be no overrun cities anytime soon.

Oh, no. You know, I just watched for the second time last week's "Game of Thrones" with the White Walkers coming over the hill, and I thought, "We could not afford one page of that sequence!" But we're trying to do what we can do and hopefully do it pretty well.

It must be very different doing this kind of genre show as opposed to something like "Veronica Mars," which you and your co-developer Diane Ruggiero-Wright both worked so much on. That was a mystery show where all the clues for the whole season had to be planted in the very first episode, and while this is a procedural, it seems that you have the leeway to let the long story develop organically. Were there any instances over Season 1 where you said, "I never thought we'd be talking about this idea or character, but now we use them every day"?

This is insane as a quote, but I've been really pleased with how well we ended up casting this. There's no one that we're not happy to go to at any time, which is not always the case on a show. That's particularly the case with Rahul, who plays Ravi. This is a role that's grown because we all love this guy, and it's a better show the more Ravi is on it. So we have to figure out ways to get him out of the morgue, which we didn't expect to be doing at the beginning of the year. Let's get him involved in other storylines and not go too many pages without seeing him.

I already spoke about how we spent the year gravitating more towards the zombie mythology week after week. Doing "Veronica Mars," it was a detective show, and so that was the genre. We were doing a noir mystery with a gumshoe element and real red herrings. We wanted the show to have a "play at home" game almost. We'd put the clues in the show, and the savvy audience member could figure out the mystery with Veronica. But on "iZombie," Liv has these sort of magical visions that can shortcut things, and the frustrating thing for me is that cops are supposed to be able to prove things. With Veronica, she could just get a piece of information in hand, and then she'd clap her hands and be done with it. With a police show, trying to get a piece of evidence that you could use to prosecutor someone in court is a pain in the ass. [Laughs] It made me understand why in something like "Law & Order," everyone just confesses at the end. So now our goal is to have maybe one red herring and then use a really solid piece of information to wrap that criminal up so we can get back to the zombies in deep freeze.

One thing you spoke about early in the development of the show was doing your personal take on the Buffy archetype -- taking the idea of a young woman at a specific time in her life and using the fantastic stuff to dig at the character. Liv's story was so much about a quarterlife crisis -- realizing that she's not quite ready for adulthood as she thought. How does the finale help either resolve or evolve that idea?

It's an angsty sort of idea, the quarterlife crisis. And that's fine. We liked playing that as a long arc theme for Liv in Season 1 -- but I don't think you can keep playing it. If we were having her reluctantly diving into these cases or feeling sorry for herself for too long, I think fans would get tired of that naval gazing from the character. So I'd say that as we pick up Season 2, she's sort of accepted who she is. She's not in great shape at the start of Season 2, but I think it's more about her personal relationships and where they stand at the end of the year rather than grousing about being a zombie and how all her plans have been derailed. I think of her in Season 2 as being more in the new normal -- or just the normal.

One of the things that seems to have evolved over the season as well is the idea of synching the brain she's eating with her own personal story from being a sniper when she needs to kill someone to being an alcoholic after someone close to her dies. Do you feel like you've gotten better at that kind of storytelling as you've gone along?

Yeah. Back when we were doing "Party Down," the most fun we'd have would be those couple of brainstorming sessions where we'd be going, "What is the party of the week? It's a pet wedding!" You'd just put these ideas up on the board of "What would be funny? What would naturally create comedy?" Now with "iZombie" we get to do the same thing with "What brain do we want Liv to inhabit at some point this year?" and you start to put all of them up on the board. And I think we break murder cases differently than most shows with a case of the week format because other shows are taking a compelling murder mystery and starting from that point. Our starting point is what would be fun for Liv to channel.

I kind of equate it to "The Big Lebowski," which I've referenced in so many other shows that I think people are tired of seeing me do it. [Laughs] But the first time I watched that movie, I felt unsatisfied at the end because I was really tracking the mystery of it. I was invested in the detective case. But then on subsequent viewings, I realized that it's all about the fun ride. That's what the Coens are doing there. It's all about the ride you're on, and that's the kind of path we take on "iZombie." There are plenty of detective/murder-of-the-week shows out there. Let's find a fun way inside of it.

And I feel like that allows Rose McIver to get to some almost "Orphan Black" levels of character work. When she was a stoner, I thought, "Yup. Nailed it."

[Laughs] Yeah, if I had to submit an Emmy tape for Rose, I would submit last week's episode. I loved her as both cheerleader and stoner.

One of the ways in which TV has evolved in the binge era is that shows are encouraged to take more risks and shake things up with their finales. You've got the eternal question of someone becoming a zombie in there as well as Major in a tight spot. What can you say about how the finale will take what we know and complicate it in a way that sets up Season 2?

I will say that I'm a believer in season finales that pay off, which is not to say that everyone is going to love the choices we make. But we have taken the audience on this journey this season. We've been telling these stories and building momentum, and I wanted to give a sense of completion. We also tee up storylines for a future season, but I really wanted people who have been watching all year to go, "Oh yeah! This is what I wanted to see happen" or "I wanted these storylines to come to fruition somehow." I hope we've delivered on that.

And I think that when we see the final episode, we'll see that the show will definitely be going off in some new directions for Season 2.

"iZombie's" Season 1 finale airs tonight at 9:00 E/P on The CW.