Paul Haggis is a tricksy sort of writer-director. Watching In the Valley of Elah, in which Tommy Lee Jones investigates the death of his Iraq veteran son, just when you've imagined all kinds of conspiracy theories, you encounter a sucker-punch. In The Next Three Days, a community college professor, of all people, plans to bust his wife out of jail. And just as you've settled into Million Dollar Baby's Lady Rocky groove, the film springs a surprise.

“I love the idea of playing with genre,” says Haggis. “I’ve always loved that idea. I grew up watching the films of the 1960s and 1970s that played with genre. Since that period, I’ve become really quite tired of seeing the exact same plot over and over again.”

It wasn't always thus. The early years of Haggis's career were dominated by tropes. Born and raised in London, Ontario – London-on-the-Thames, no less – Haggis was inspired by Michelangelo Antonioni's Blow-Up to move to England and pursue fashion photography. He later returned to Canada to study cinematography and from there he relocated to LA, where he spent decades knocking out episodes for Diff'rent Strokes, The Scooby and Scrappy-Doo Puppy Hour, The Love Boat, Thirtysomething and LA Law.

“I learned my craft,” he says, laughing. “I can’t complain. For all the restrictions that come with situation comedies, I was very fortunate to get it. And it means I understand structure very well. And that allows me to break the rules.”

He could have remained in TV, where he scored huge global hits as the creator of Due South and co-creator of Walker: Texas Ranger for Chuck Norris. But Haggis remained a cineaste, a fan of such post-classicists as Jean-Luc Godard, Sydney Pollack and Federico Fellini.

When he finally broke into movies, he did so with no little aplomb. In 2006, he became the first screenwriter to write two Best Film Oscar winners back-to-back: Million Dollar Baby (2005) directed by Clint Eastwood, and Crash (2006), directed by himself.

He might have made it three-in-a-row with his dual screenplays for Eastwood's Flags of Our Fathers and Letters from Iwo Jima (2007). He scored a Bafta nomination that same year for Casino Royale.

Departure from the Church

Oddly, in recent years, these achievements have almost been eclipsed by his departure from the Church of Scientology. The church's support for California's homophobic Proposition 8 was the catalyst. He had been a member for 35 years and had made it "all the way to the top" of Scientology's study programme. His subsequent hounding by church members was recounted in great detail in the 2011 New Yorker piece, The Apostate.

“I still get upset about it,” says Haggis. “But I can’t just direct that at the people who kept me blind. It was so obvious to everyone that I had been indoctrinated by a cult. But not to myself.”

Third Person is Haggis' first feature film since leaving the movement. The project required five-and-a-half years and was produced independently by Haggis.

“It was a very frustrating process,” says the film-maker. “But I knew the film I wanted to make. I wanted to make something with as many questions as answers. Because as I get older I’m less certain about everything. I’m happy that I got to make the film this way.”

A return to the choral structure of the Oscar-winning Crash, Third Person focuses on three hotels in three cities. In Paris, Liam Neeson's damaged Pulitzer Prize-winning author hopes to hook up with his mistress, played by Olivia Wilde. In Rome, businessman Adrien Brody falls for an Albanian gypsy. In New York, Mila Kunis starts a new job as a maid in an effort to gain access to the son who has been removed from her care.

“It’s the characters’ fault,” Haggis says laughing. “I start out writing one thing and they turn it into something else. And I’m just following along.”

The new film ultimately coalesces into an exploration of how writers exploit biography. “We are thieves,” says Haggis. “Often you’re writing about things that are completely alien to you but there’s a line here that was taken from someone you know. You might have distorted it or changed context. I do feel quite guilty sometimes. But I’m not sure I’m apologising for it. This is who we are. We’re vampires.”