M. Night Shyamalan breaks movie-making mold with new thriller 'Glass'

LOS ANGELES (KABC) -- Filmmaker M. Night Shyamalan wrote and directed the new movie "Glass," a follow-up that combines two of his previous thrillers: "Unbreakable" and "Split."

Returning from those films to star in "Glass" are James McAvoy, Samuel L. Jackson and Bruce Willis. Their characters find themselves institutionalized, and the trio plot their escape by harnessing their individual "skills."

To reprise his role as Kevin Wendell Crumb, McAvoy had to embody not one but 23 characters.

"When I read the script for 'Glass' and saw that there were 23, there's 20 in the final film, but there were 23 in the original script," said McAvoy. "I did phone Night immediately and go, 'Are you certain that I really need to do this?' And he was like, 'Yes I am,' and I was like, well let's do it then.'"

Jackson said acting alongside McAvoy and seeing him transform into those multiple characters was a bit daunting.

"As an actor, it's intimidating. You're sitting there going, 'Can I do that? Can I just switch from person to person like he's doing?'" Jackson said.

Those many personalities range from a 9-year-old boy to a woman and to the violent, destructive "beast." McAvoy utilized a professional trainer who he jokingly dubbed "the Viking" to put him through an intense fitness program.

"He made me eat a ton of food, alot of carbs -- more protein but more carbs than I thought I'd ever eat my life -- and working out five, six times a week, lifting a lot of weights, pushing a lot of weights, pulling a lot of weights," said McAvoy. "It was actually really interesting and fun to do something that different and extreme with my body that I've never done before. And I'm nearly 40, do you know what I mean? I don't know if I'll do that again, so it was it was cool."

"Glass" is rated PG-13 and is in theaters now.