(CNN) -- If you saw Joseph Gordon-Levitt in "Premium Rush" or "The Dark Knight Rises" this summer, you will be surprised at how different he looks in "Looper," a hit-man thriller with a time travel conceit.
Gordon-Levitt looks older and more mature somehow: with a high forehead, a more pronounced nose and a way of pursing his lips in a faintly ironic scowl. The reasons for his makeover become apparent when his character, Joe, comes face to face with his older self, played by Bruce Willis: higher forehead, same nose, same scowl.
It's enough to put even the sharpest hit man (or "looper") off his aim. And Old Joe gets away, which is a problem, because if Young Joe doesn't rectify the situation and fulfill his contract, he won't qualify for the 30-year retirement plan that's allowed Old Joe such a long and fruitful life. They'll both be cut off in their prime.
The first film in four years from "Brick" and "Brothers Bloom" writer-director Rian Johnson, "Looper" is a smart suspense movie. It's essentially a low-tech variation on themes from "The Terminator" but ingenious enough to feel fresh, intriguing and even bewildering at times.
Most flicks are so predictable, you could set your watch by them ... if you still had a watch (Joe has a silver pocket watch, but he's a slave to retro fashion). Johnson adopts an arrestingly bold and unusual structure, introducing two major characters an hour in and employing telekinesis when it seems the time travel thing is getting old.
But his readiness to make us stretch should not blind us to the fact that "Looper" is full of holes: time holes, holes for corpse disposal, and enough plot holes to fill a leaky bucket. It is set, confusingly, 30 years from now, in a low-budget future that looks like a more broken down version of our present (give or take a few flying motor vehicles).
Time travel has not been invented, but in another 30 years, it will be -- that is, in 2070 -- and the Mob has taken to sending their marked men back in time to be dispatched by loopers and disposed of in Joe's less-regimented present.
Confused? You will be.
It doesn't matter. It doesn't even matter that nobody thought to make Gordon-Levitt's earlobes resemble Willis' (if you've seen "The Imposter," you'll know that's a dead giveaway). It's fun being flummoxed, and Johnson has a knack for pulling off short, snappy scenes that keep the drama percolating (the excellent supporting cast, including Emily Blunt, Jeff Daniels and Noah Segan, also helps).
Yes, it's a B movie sci-fi thriller, but not many prestige pictures have this much going on underneath the surface.