Brian Truitt

USA TODAY

It’s the end of the world — and the series — as The Leftovers knows it. But so far, Damon Lindelof is feeling fine.

“We’ll see what happens when the reviews start to come in and people see what actually happened,” says the executive producer of the cult HBO drama, which begins its third and final season Sunday (9 ET/PT).

Based on Tom Perrotta’s 2011 novel, Leftovers began its run with a rapture-like event leading to the disappearance of 140 million people — 2% of the world’s population — and its effect on police chief Kevin Garvey (Justin Theroux), his family and their small New York town. Season 2 found Kevin, girlfriend Nora Durst (Carrie Coon) and preacher Matt Jamison (Christopher Eccleston) among those who try to move forward by relocating to Jarden, Texas — deemed “Miracle” since no one in town was taken on that fateful Oct. 14.

But the situation looks bleak again: The eight-episode season starts as the main characters prepare for the seventh anniversary of the Sudden Departure two weeks later, and what everybody widely presumes will be the apocalypse. Leftovers also shifts much of the action to Australia, where Kevin’s slightly crazy dad (Scott Glenn) is on his own personal mission to ready for the end times.

“All these characters are spinning as a result of the Departure happening and everything that they do is helping them get some level of self-control as they move forward,” says Lindelof, best known for his role as an executive producer of ABC's Lost. “But what they’re not doing is listening to one another or allowing each other to give them comfort.

“That’s probably the cautionary tale of the season: You’re not in this alone.”

The Leftovers has always taken a “deep dive” on love, life, loss and grief, Theroux adds, but it’ll be remembered for its “very courageous, noble swing at ‘What is the meaning of life?’ ” He likens the series to a Chekhov play, “where not a lot happens and there’s a lot of characters wondering what they should do, but it somehow scratches this really deep, philosophical, theological thing of ‘Why are we here? What is the point?’ In our show, everyone has different reasons and reactions to those questions, and no one really has the answers either.”

The series has never been about solving mysteries, so Lindelof admits the finale won't provide a big reveal about where everybody went and why. “That’s not going to happen. We’re taking that off the table.” But will it be as polarizing a climax as Lost? “That’s a high bar, man,” Lindelof says, laughing. “I’m the least qualified person in the world to predict what the audience is going to think about the ending.”

Theroux feels it’s satisfying and surprising, while Coon figures that fans will find the show’s goodbye quiet, personal and very grounded.

“Really, it ends up being about relationships and making meaning and how meaning actually exists between people. The bottom line is always love with Damon,” Coon says. “There will be critics, for sure, but the thing I’m certain of is there will be a conversation about it.”