A story set in 2044, about assassins whose targets are sent back from thirty years further in the future, Looper is a very intricate sci-fi. How did you approach writing it?
Writing the screenplay, part of what I wanted to do with it was really focus on getting the script as tight as possible. Part of the pleasure and I hope some of the charm of [Johnson’s last film, The Brothers Bloom] was its unwieldiness. The fact that it’s this big, rambling carnival of a movie. Coming out of that, the challenge was to do something that was very, very focused. I ended up spending a lot of time revising the script, more than I’ve done with any other.

Did writing a time-travel movie give you a real headache from a logic point of view?
It was definitely the most unwieldy part of writing the script. The tough thing was less about coming up with flourishes, and more about taming the exposition. I guess at the end of the day, that’s where time-travel always becomes a sticky-wicket, in terms of writing. Once you’ve come up in your head with this whole structure, the temptation is to explain it all to the audience. But once we started showing it, it was a real pleasant surprise to see that audiences didn’t need that.

What are your favourite time-travel movies?
Twelve Monkeys is fantastic.  I’m such a huge Terry Gilliam fan, and the phantasmagoria of how he deals with the complications of the loops and the emotional places he takes it to at the end of that film are hard to beat. I think the first Terminator also. The way it used time-travel specifically is something that I’m drawing from: how it’s part of the set-up but not an active part of the plot. I also think the first Back to the Future is almost a perfect script. It really holds up. They should really be studying that script in film schools.

Bruce Willis plays one of these mob targets, sent back in time to be killed by his younger self. Did you cast Willis with a nod to his role in Twelve Monkeys?
No, not specifically. It might have even been a little frightening, that connection, just because Twelve Monkeys is such a seminal time-travel movie. Drawing comparisons is incredibly dangerous in my mind. The one thing that did tie in specifically with Bruce, and what he’s done in the past, was just the fact he was Bruce Willis. The fact that, aside from being a tremendous actor, he has that Bruce Willis thing, where – when he shows up in a movie – he’s typically the hero who is going to find the right person, kill them and save the day. And that played really strongly into where his character ends up going in this one.

Joseph Gordon-Levitt plays Bruce’s younger self, and apparently listened to recordings of his co-star to ape his voice. How did Willis react to that?
He loved it. The diner scene was the first time we really sat those actors across from each other, and that was about half way through the shoot. I think Bruce made some comment to Joe like ‘Ah, you sound like me!’ Something very understated and very Bruce Willis-ey. I think he got a kick of it.

How did you approach the look of the film – specifically designing what our future world will look like?
What I wanted to avoid was design fatigue. I feel like we see a lot of movies, especially since the advent of CG, which makes it affordable to create these instant landscapes – and I feel like we see a lot of sci-fi worlds. To me, it was more interesting to ground it, to take our world and tweak it by ten percent, so it’s recognisable…but there are just a few things that are off about it.

Arriving on the back of a summer of remakes, sequels and reboots, Looper feels very fresh. Do you think Hollywood lacks originality now?
I don’t want to broadly shit-talk a big group of movies. Some of the best films that have ever been made are adaptations. There’s nothing to say that just because it’s an existing property, you can’t turn it into a really amazing, original film. But I think there is a certain amount of re-cycling, during this phase that we’re in. I know for me personally it’s much more interesting, just as a storyteller, to grow something from the ground up.

What would you say to your future self if you met them?
To my future self? I’ve been asked about my younger self, but not my future self…oh God. I’d would ask him to bring me back a sports almanac.

Looper is on general release from Fri 28 Sep.

Looper - International Trailer (HD)