"That was really scary because you commit to that and there's no real way out of it," said "Looper" writer-director Rian Johnson of using practical prosthetics to make one actor look more like the other. "But the biggest thing is Joe's performance, he's really doing Bruce in a big and daring way, but he strikes a balance between obviously imitating Bruce and also building this organic performance."
As for the mechanics of manipulating the space-time continuum, Johnson admitted, "Time travel just never makes sense."
He added, "If you just tell somebody the plot, you're inevitably telling them the time travel stuff, but the movie actually uses that as a set-up. The best parallel I can draw is to the first 'Terminator' movie where time travel is used to set up this impossible situation between these people and then that situation plays itself out."
"Looper" opens Sept. 28.