“At the same time, it was very important for me to have everything make sense. I didn’t want Looper to be a puzzle box movie. I wanted this to be much more of a ride. That’s why it’s so much fun to work in established genres. They give you a kind of pre-built chess board to play on. And they give you rules that both you and the audience already know. That gives you a lot of leeway, not just with the time travel stuff, but also action-movie logic.”

There is a lot more to Looper than a simple chase film — we haven’t even mentioned the telekinesis yet — but one of the most startling things in the movie are what Willis’ Joe will resort to in order to change the past so he no longer needs to execute himself, including a shocking act most stars of his caliber would never agree to perform, even if it happens off-screen.

“I totally expected there to be a big discussion with Bruce about that scene,” Johnson says. “But the only discussion we had was how excited he was about the extreme places this character went to. He wasn’t apprehensive about it, and he wasn’t protective of his movie-star image, either. I think that’s part of what turned him on to the project — the rawness and the desperation of his character. He’s really a great actor, and he was 100 percent into the role. Thank God I was able to talk him into doing that!”

Gordon-Levitt spent three hours in the makeup chair each morning donning subtle prosthetics and make-up to help him resemble a younger version of Willis. The effect is initially startling — you know it’s Gordon-Levitt playing the part, but he looks so different — but it ultimately helps sell the illusion that the two men are playing the same man.

The actor says he remembers Johnson talking about Looper with Johnson as far back as the filming of Brick and being intrigued by the moral complexity of the piece.

“He wrote the part specifically for me, which is the first time someone has done that,” Gordon-Levitt says. “The first time he showed me a draft of the completed script was two years ago. Normally you get the script a few months before shooting, so it was unusual to be involved with a movie like this from such an early stage. It’s a really smart story about how violence begets violence. People do horrible things, but it’s never actually as simple as good guys and bad guys. Real life is much more complicated than that.”

But although the actor was excited about his role and reuniting with his director friend, when Willis signed on Gordon-Levitt really went over the moon for Looper.

“When I heard he was going to do it, I was thrilled, because he is so perfect for it: A guy who is 30 years older than me but believes he could still beat me in a fight! There are probably not that many 60-year-old dudes out there who could beat me in a fight! But he could do it. Maybe.”