Looked at in one way, Kevin Garvey, the main character of HBO's wonderful drama The Leftovers, came back from the dead twice in the course of the show's tremendous, just-completed second season.

The first time — in the dreamlike episode "International Assassin" — he drank poison. It sent himself into the afterlife to face off with former cult leader Patti Levin, in order to finally rid himself of his hallucinations of her. The second time — in the season finale — a gunshot sent him back to the hotel that acts as a purgatorial way station. One there, he was forced to literally sing for his survival. (Somehow, he — and Justin Theroux, the actor who plays him — pulled it off.)

Of course, one of the joys of The Leftovers is that this could all be explained rationally. And solid, logical Kevin, who began the series as a seemingly well-adjusted police officer, might have been just the guy to do that explaining in the past. But in season two, Kevin embraced the darker side of himself, pursuing his demons even to the (literal) end of all things. It was bold storytelling, and Theroux's work was emotionally open, almost nakedly vulnerable at times.

In the wake of a finale that saw the character finally embrace the little town of Jarden, Texas, as his new home, I got on the phone with Theroux to ask him about singing in front of a crowd, Kevin's quest to rid himself of Patti, and just how he thinks Kevin probably deals with his slow descent into the seemingly supernatural.

This interview has been lightly edited for length and clarity.

On singing: "Although I don't sing like Patti LaBelle, I can at least identify with her a little bit now"

Todd VanDerWerff: What was your first thought when you realized your big emotional climax in the finale involved singing karaoke?

Justin Theroux: Sheer terror! [Co-creator] Damon [Lindelof] knows very well that not only do I not sing, which is evident in my performance. [laughs], but being in the spotlight, being at a microphone, public speaking, and singing are probably my four top, least favorite things to do, and he made me do all of them. Even in the script, he wrote, "Kevin steps to the microphone and begins to sing. (Yes, Justin, you're going to have to sing.)" So he knew he was pushing me as far out of my comfort zone as possible.

I've had to be vulnerable in the show, but it's usually opposite one other person, at tops two. To do it in front of a room full of other actors, sitting at tables, was daunting to say the least.

TV: What's different about tapping into your vulnerability in front of a crowd, instead of with just another actor?

JT: The one thing that I was surprised by was that I was able to connect to the music [Simon & Garfunkel's "Homeward Bound"], which is very emotional.

"When you're at a microphone, booming across a room, it's terrifying"

When you're working across from another actor, it's a bit of a tennis match as far as just making sure the ball goes over the net to each other. When you're at a microphone, booming across a room, it's terrifying. When you see the great divas singing, tears streaming down their cheeks, like Patti LaBelle, you realize they're being really moved by the music and the words. Although I don't sing like Patti LaBelle, I can at least identify with her a little bit now.

On his character's journey: "He's very good at living in his present, even though it's an uncomfortable present oftentimes"

TV: So much of this character's journey is about being a rational man in a world that operates by fantastical logic. How have you built that journey from a man who was much more skeptical to someone who's much more open to that sort of belief?

JT: I've always considered him agnostic, if not an atheist. In the first season, he has concerns about where the percentage of the population [who disappeared in the show's storyline] went, but I think it was more about keeping his foxhole safe and protecting his daughter and his family, and also trying to reattach limbs [to his family tree], as far as his son is concerned and his ex-wife is concerned. He wasn't wanting to start over but wanting to bring things back to him that he had neglected or been ungrateful about.

In season two, it's obviously very different, because he's haunted by this — to him — very real person whom he knows is dead, because he saw her die and buried her. And this fantastical thing has happened where she appears to him and sits beside him and barks at him and yells at him and even physically abuses him at times. Once the cork comes out of that bottle, all bets are off. You understand that you are no different from that person you drive by on Seventh Avenue who's standing there with tears streaming down their face screaming at nothing.

"You understand that you are no different from that person you drive by on Seventh Avenue, who's standing there with tears streaming down their face, screaming at nothing"

I think trying to keep a grip on that side of yourself and run a family, it's where the rubber hits the road for that character in such a great way. How do you have a conversation with your daughter? How do you tell anyone you're going to be all right? How do you tell your girlfriend you're going to be a stand-up, great guy? You become unavailable, because you literally have a whole side of your life that they don't know about, even after saying that you're going to be really honest with each other.

TV: What was the move to Texas like for the cast as an acting company?

JT: It's always nice when a company can move to a location, because in a weird way you become more of a family than when we were in New York, where everyone goes back home [at the end of the day]. On the weekends, you'd go back to some semblance of your life. But when you're in a place like Austin, which I think we all unanimously adored, something else happens, and you gel in a way that you get that shorthand, where you become more like a real family. It's a carnival, circus-like mentality.

You rely on each other. We made a couple of friends in Austin, but we largely clung to each other, and I think that's always helpful. It's nice to finish on a Friday night — not that we ever finished early on a Friday night — and go tip back a glass of wine with them and talk about the week and the week to come.

TV: So much of this season was about Kevin's journey to find his own identity. What did you discover about this character through his search for who he truly is?

JT: On the one hand, I want to say I haven't discovered that much about him, because he's just being a human being, bumbling through life, trying on different clothes and approaches, trying to be hard sometimes and soft other times. He's just trying to do the right thing.

"I'm loath to say he's reached any sort of moment of cathartic bliss, because I don't think he has"

There's so many things zooming at 45,000 feet above the show. Themes that are spiritual or practical. Fatherhood, family, hope, belief. Damon and [co-creator] Tom [Perrotta] were taking enormous bites out of that pie, and it was very courageous of them to do that. Kevin is really just one component of all that. I'm loath to say he's reached any sort of moment of cathartic bliss, because I don't think he has. I think our season ties up very nicely, in a really satisfying way, but much like life, you can have an experience or a job that ties up very nicely, but it doesn't mean you're protected from anything moving forward.

Related The creators of The Leftovers discuss tracing religion back to its ground zero in season 2

What I like about Kevin is that he's very good at living in his present, even though it's an uncomfortable present oftentimes. I like the way that Tom and Damon pushed him into these corners and the logic that they used to make him squirm out of them.

After he'd gotten very sound advice that he was mentally ill, he decides to go drink poison. It's not the most logical thing, but to Kevin's mind, that is the correct thing. I don't think he believed he was mentally ill. At the end of that scene with Laurie, he's still protesting and saying, "Well, what if Patti is real?" So if you can say anything for him, he's very much his own man. He's trying to do the correct thing, even though his daughter, his girlfriend, and his ex-wife were telling him otherwise.

On Kevin's past, present, and future: "We always thought of [Kevin and Patti's] relationship as this bizarre, chaste romance"

TV: That final moment with Patti in the well was so pivotal. How did you and Ann Dowd find your way to how powerful that scene became?

JT: I cannot say enough things about how much I love that woman, Ann Dowd; that character, Patti Levin; and that relationship. I've said this before, but we always thought of that relationship as this bizarre, chaste romance. They orbit each other in this great way that mirrored an incredible love story.

"It was a devastating scene to shoot. Ann and I were hugging each other all day long."

The fact that this incredibly damaged person [Patti] was really asking to be guided, in a weird way, to her end I thought was just a stroke of genius. I remember reading that script and being so moved, and being devastated, because I think that's a real death [even though it happens in what may be the afterlife]. I wanted to get on the phone with Damon immediately. The practical side of me was going, "We have to get Ann back." I wanted her as my friend there on set with me, and I wanted the character to live.

But one of the things that makes it so brilliant is that's not the way we get to live our lives. When people die, they die, and they don't come back. It's an incredibly unsettling feeling when death happens. I felt very much the same things when I read it and performed it with her, and it was a devastating scene to shoot. Ann and I were hugging each other all day long.

TV: That relationship with Nora has been put under a lot of strain. How do you and Carrie Coon understand that connection and how it frays?

JT: In truth, we actually didn't even have that much together. She was off doing a lot of things, and I was witnessing it, and I was off doing a lot of things, and she was witnessing it from the other side of the glass. So we weren't communicating that much, which I thought was kind of interesting. I was ostensibly having another relationship with someone, again not romantic, but my time was being spent containing a whole other side of myself that she didn't get to see.

You'd have to ask Carrie this, but I think Nora's thing is trying to create that nuclear family again, whatever it looks like, with an adopted baby, a daughter that's not her own, a stressed-out boyfriend. She impulsively forces herself into these situations. She impulsively buys this home. She demands things. She's not entirely sorted out, either! [Laughs.]

So I don't think her move to Miracle was like sitting on a therapist's couch for 15 years, either. Everyone brought their issues with them. They just manifested themselves in different ways. I think she used the opportunity of what she would consider Kevin's mental illness to take the scrap of family that she had, which is Lily and Matt and Mary Jamison, and start over again. She's an incredibly strong-willed character in the show. Kevin is, too, but he's put upon in a different way and can't focus on family.

TV: You've also had quite a bit of success writing for the screen, for movies like Iron Man 2 and Tropic Thunder. How do you think your writing informs your acting, and vice versa?

JT: If anything, sometimes, I can step back a little bit and intuit a little bit what Damon and Tom were going for. Any actor can do that, though. It doesn't necessarily have to be a writer.

"I wouldn't ever change anything [in the scripts]. I wouldn't want to move too many commas around."

But what they do is so wildly different from the kind of writing that I do. I'm just astounded by the scripts that they hand in. If there's anything I know, just because of how clean those scripts come in, is how labored over they were. You can spot a script immediately when a writer has phoned it in. There's so much connective fiber in these scripts that on second, third, fourth readings and then of course in the viewings of them, I'd be, like, "Holy shit, these guys really did create a tapestry of something very special."

They had long conversations before even putting pen to paper about what are the themes that they really wanted to bite down on. When you really turn something over and over in your hand and attempt to examine it before you try to write, I think it's always time well spent, because then you have a sense of true north of where you're going when you write it. That paid dividends for them. When we'd get the scripts, I'd be, like, "Holy shit. These are just perfect." I wouldn't ever change anything. I'd occasionally change a conjunction, but aside from that, nothing else. I wouldn't want to move too many commas around.

The second season of The Leftovers is available on HBO Go. Come back tomorrow for a lengthy chat with Leftovers co-creator Damon Lindelof.