It’s a small fraternity of directors that have taken on the formidable task of helming a time travel movie. Between the potential for audience alienation that comes with heavy duty science fiction, and the third rail of time travel physics, it’s a wonder the group isn’t even smaller—which it is, when you amend the qualification to successful time travel movies. Measuring success in a time travel movie means measuring the success of the explanation of time travel alongside all the other stuff that a movie has to do well. It means walking a tightrope; a tightrope that Director Rian Johnson describes thusly, “On one hand, the sci-fi nerd in me feels there’s a danger not explaining [the time travel], because it can look like plot holes. On the other hand, the story guy in me is like, ‘You know why that’s there, and that’s not what’s important to the story.'” This is the central dilemma for Looper as a film, this balance between saying too much and not saying enough. Because while Johnson spends much of the film’s duration astounding the audience with an exceptional grasp of storytelling and world-building, his ambivalence about the film’s central device ends up blurring the whole.