Heist thrillers are built on plot twists and turns, but in Triple 9, the unexpected is initially provided by seeing actors playing against type, from Kate Winslet as the ruthless leader of a Russian mob to a brawny con-man version of the typically cerebral Chiwetel Ejiofor to Casey Affleck as a cop on a mission, a role that further elevates him beyond the status of "Ben Affleck's brother."

However, some of Triple 9's most nail-biting and surprising moments ultimately belong to Anthony Mackie, playing a crooked cop named Marcus Belmont who's starting to develop a conscience — or perhaps not, with the audience kept guessing throughout the movie.

"As an actor, that's what you want: you want the audience to start seeing those layers fall off," said Mackie told CBC News ahead of Triple 9's Toronto premiere. 

"When I read this script, it was interesting. Every 10 pages, another layer fell off and you really got to see this guy for exactly who he was by the end of this movie."  

Anthony Mackie

Anthony Mackie, seen at the 2014 Toronto International Film Festival, has built an acting portfolio that includes both blockbusters and grittier indie fare. (Mark Blinch/Reuters)

Aside from his character's complexity, Mackie was also drawn to the project because of its all-star cast, rounded out by Woody Harrelson, Aaron Paul and The Walking Dead's Norman Reedus.

"What John Hillcoat, our director, did was put us in a position where there was no competition. He literally gave everybody their moment," Mackie said.

"So you can see their moment of humanity, their moment of recognition, and he gives all of us that in this movie, which is kind of remarkable with such a large cast."

A career in high gear

Mackie, 37 and Julliard-educated, is no stranger to being a team player in an ensemble cast.  He appeared as Falcon/Sam Wilson in four Marvel comic book adaptations, with a fifth — Captain America: Civil War — on the way. Those blockbuster roles are offset by nuanced and gritty performances in dramas: he played Sergeant JT Sanborn in Kathryn Bigelow's Oscar-winning The Hurt Locker as well as Tupac Shakur in 2009's rap-wars biopic Notorious.

Despite having a career in high gear, the cheery and gregarious Mackie turns solemn and somewhat pessimistic when conversation turns to Hollywood's hotly debated lack of diversity.

"We've been having this argument for a long time," he said. 

"We had a conversation about Woody Allen and his movies: living in New York and literally everybody except for Hazelle Goodman was white and between the ages of 25 and 35. So it's not a new argument."

He wishes more filmmakers followed the example of Triple 9 director Hillcoat.

You have a group of rogue cops: you have a Latino, you have two black dudes, you have two white dudes. it's the way the world looks as opposed to the way we see the world - Anthony Mackie on diversity in heist thriller Triple 9

"He never cast anybody from a racial perspective," Mackie said of the Australian-born director. 

"Woody Harrelson's assistant detective is an Asian woman. You have a group of rogue cops: you have a Latino, you have two black dudes, you have two white dudes. It's the way the world looks, as opposed to the way we see the world."

Hillcoat also mixed in an English rose that left Mackie star-struck: the Shakespeare-loving actor has been a longtime fan of co-star Winslet.

"I didn't think she was in the movie. I thought they just said that to get me in the movie," he laughed.

Triple 9 opens in theatres across Canada on Friday.