TORONTO -- Rian Johnson devised his own method for keeping track of twin futuristic time periods and one character played by two actors, Joseph Gordon-Levitt and Bruce Willis, in "Looper."
"I had an intricate system but, at the same time, I didn't want the film to feel like algebra homework. I wanted it to be an accessible film where, at the end of the day, the payoff is an emotional one. It doesn't feel like a puzzle resolving," the director-writer said.
After coming up with the structure, though, he had to discipline himself as a writer "to say, OK, but I don't have to explain this to everyone, I don't have to show everybody how clever I've been. ... I'm just going to let the mechanics of it play out and let the audience see the results of those mechanics and let the characters experience and deal with it."
"Looper," about a younger hitman charged with killing his older self, was selected for the coveted opening-night slot at the Toronto International Film Festival. Mr. Johnson admitted to going into a "bit of a fugue state" over the scale of the star-studded event, with formal introductions and red carpets and a mob of photographers and, of course, giddy moviegoers.
On this day, he was doing nonstop interviews at the five-diamond Ritz-Carlton hotel, only able to glance at the sunny bustle outside through a wall of windows.
Mr. Johnson had enjoyed festival success before, but not at this level. His first feature, the dark, moody mystery "Brick," was a surprise hit when it premiered at the Sundance Film Festival in 2005. Mr. Gordon-Levitt played a high school loner who plunges into his small town's underbelly to find his ex-girlfriend's killer.
His next movie, "The Brothers Bloom," starring Adrien Brody, Rachel Weisz and Mark Ruffalo, was about a swindler who falls in love with the eccentric heiress he and his brother have chosen as their final mark before quitting con games.
"Bloom" was a bit of a "big, rambling, traveling carnival of a movie," and afterward, Mr. Johnson dug out a three-page script he penned a decade earlier for a short film he never made. It had the narration that opens the movie and a foot chase between the older self and younger self with talk about moral conundrums, and it launched "Looper."
Mr. Johnson wrote "Looper" with Mr. Gordon-Levitt in mind, "in that this would be something cool we could work on, this is going to be something fun we can engage in." Of course he was just half of the equation, playing a hired gun named Joe as a young man, with Bruce Willis cast as Old Joe.
"He loves being a chameleon," the director said of the actor who most recently appeared in "Premium Rush" and "The Dark Knight Rises" and channeled Channing Tatum's Magic Mike on "Saturday Night Live."
"As much as he has movie-star charisma, he's really a character actor at heart. He loves disappearing into roles, and this was literally disappearing into another; he's putting on somebody else's face."
Mr. Gordon-Levitt, still boyish at 31 years old, spent three hours in the makeup chair daily to alter the bridge of his nose along with upper and lower lips and turned his brown eyes blue with contacts. The younger actor came up with the gesture where he checks his hairline, a sign of what's to come for Old Joe.
Some critics suggested Mr. Johnson need not have bothered with the makeup, but he says, "I felt like it was important to give some kind of hand hold for the audience to grab onto or some kind of foreignness to his face. It was also just fun. ...
"If someone feels the makeup was unnecessary, the positive side of that is that means they feel Joe's performance was strong enough so that you didn't need it."
"Looper" also stars Jeff Daniels as a crime boss, Emily Blunt as a woman living in a farmhouse where Joe takes refuge and Pierce Gagnon as her young son. The director also cast his dad as a club bouncer who gets shot by Mr. Willis near the end of the movie; euphoric at his son's foray into the movies, he nailed his scene.
It was Mr. Daniels' performance as a blind man with a keen sense of humor and ability to suss out a con or phony in "The Lookout," also starring Mr. Gordon-Levitt, that convinced the director to cast him.
"But I mean everything I've ever seen Jeff Daniels do is also the answer. He's got that easy charm," and didn't seem to be against type. "He's not written as a traditional heavy, he's got kind of a dude-like, laid-back laziness that Jeff kind of sunk into."
"Looper" makes some bold choices about children as victims or perpetrators of violence.
"I'm not a fan of violence and this is a very violent film," the filmmaker acknowledged. But he felt comfortable with the strong violence because "baked into the bones of this movie, for me, is a choice between solving the problems of the world by finding the right people and killing them, versus solving the problems of the world by raising your children."
As for the lead child, he's from Atlanta and was discovered by the movie's New Orleans casting office. "The instant I saw Pierce, it was like a bell ringing," Mr. Johnson said.
"It was one of those kid casting things you just pray for, where you get really lucky and he just popped off the screen. He would sit down and do three-page dialogue scenes straight through -- he was 5 years old when we filmed the movie, he was just an extraordinary actor."
The boy's mother worked with him on his lines, and the director says he realized early on he couldn't give him what he calls "bad kid direction," as in "Can you do that with more of a sad face?" An adult would roll his eyes and walk out of the room, Mr. Johnson said.
"Pierce looked at me and said, 'I don't know how to do that.' ... I'm talking to an actor who needs to know emotionally why he's sad," although he reverted to an antsy, rambunctious 5-year-old at times.
Much has been made of Mr. Johnson moving to another level with "Looper," but he doesn't see it that way.
"Any time you make anything, you want to do something you're terrified of doing, you want to do something you feel you haven't done before. I don't know, when you come out of any project -- and this is no exception -- you come out sort of with the feeling of, 'God, let me just get the chance to do one more and I'll get it right this time.' "
Some may say he just did.