In season one, The Leftovers established itself as one of the most engaging and befuddling shows on television. Based on the novel of the same name, by Tom Perrotta, the series follows a population struggling to come to terms with the mysterious disappearance of 140 million people.

In a plot twist worthy of the show's creator, Damon Lindelof - who made the hugely popular Lost - season two opens in a whole new setting: a small town in Texas that hasn't suffered a single disappearance. Lead actor Justin Theroux (right) tells us what viewers can expect.

So many questions are asked in the first episodes of season two. Will they ever be answered? "I think that's the appeal of this show; the questions are profound and some of them are like, 'What's the point of life?' I don't think we're going to be able to wrap that up in the finale. I think sometimes it's just Damon putting the questions out there and letting the characters walk around them. That's interesting because it's what we do in our personal lives."

Are the scripts captivating or confusing? "The scripts are gripping because he writes in a very fast-burner style and you can't help but keep turning the page. Only when I really get hung up on something will I call Damon and say, 'I don't know what I'm doing. Help me out here.' Really you just have to play the not knowing."

What do you think motivated the moving of the show to Texas? "Damon was very upfront about not knowing if there needed to be a season two. He knew he didn't want to go back to [fictional] Mapleton [the New York state setting of the first season]. I think they only wanted to do an idea that would open the show up, not just visually but emotionally, and allow them to explore something else. By the end of season one we were all tired of the loss."

Being from New York, Texas must have seemed a long way away. "In New York, when you're done shooting you have another thing happening. But when you're in Austin, there's not that much happening. Even though Austin is wonderful, it strips away a lot of the distractions and it all becomes super about your job. It gels things in a nice way because we're all in the same boat."

Your character, Kevin, spends a lot of time hallucinating. Do you try to work out which bits are in his head and which are real? "For an actor it's fun. But as a character he spends an enormous amount of time in denial that anything is ever happening. He's like the alcoholic who wakes up in the morning and has to delicately call his friends, 'Hey, I was cool last night, right?' He has a lot of those moments. The question becomes whether or not the people he's trying to love have the stomach to handle him. He doesn't want to admit these things are happening. And we'll see that when he finally has to admit them, it creates a kind of a freefall. When you live with any secret it inevitably starts to spread and pollute whatever you have. It is more terrifying to speak the truth sometimes."

You've penned comedy films such as Tropic Thunder and Rock of Ages. Has your experience on The Leftovers influenced your writing? "My writing? I write fart jokes."

The Leftovers premiered last week on HBO and will continue every Monday at 9am and 9pm. Broadcast episodes and the whole of season one can be seen on HBO GO and HBO On Demand.