Luc Besson's movies for me have always been the definition of a "guilty pleasure." They're usually big, loud, implausible action-packed adventures, often with a kick-ass heroine in a leading role (Natalie Portman in The Professional, Anne Parillaud in La Femme Nikita, Milla Jovovich in The Fifth Element). Now we can add Scarlett Johansson's Lucy to that list, although as far as B-movies go, Lucy pushes the limit pretty damn far.
It starts off in Taiwan, with Lucy as a naive college student who's being tricked by a guy she's been partying with for a week into delivering a mysterious metal case into the hands of some Taiwanese gangsters. So far so good, as this early part of the movie plays into the skeazy, underground, semi-exploitative tone that characterized the great trashy films in Besson's resume like The Professional and Nikita. He knows how to play it so that we know this is trash and he knows that it's trash, so we can all relax and experience the thrill that goes with secretly enjoying something that qualifies as pulp material. Where the nuttiness comes into play is the pseudo-intellectual gobbledygook (this is one time where I feel that term is more than appropriate) that takes over the second half of the movie, and it's so insane and at the same time ludicrously detailed, that I can't tell whether Besson really believes what's going on here or not.
See, the film is premised on the myth that humans use only 10% of their brain, so what happens if we were somehow able to channel 100%? A straight-faced Morgan Freeman (I guess there's really no other kind) plays a professor who's spent his entire career developing a theory about this notion (what an amazing waste of a career that is), but since humans actually don't use just 10% of their brain (I hope everyone reading this knows that), we're operating in the realm of total fantasy right off the bat anyway. But okay, Besson wants have fun with this and say "what if," so I'm on board with it. When Lucy hands over the case in the violent exploitation part of the first half, it turns out to be filled with bags of blue powder, and she's kidnapped by the bad guys and forced to become a drug mule, one of the bags inserted into her stomach in order to smuggle the drugs into Europe. Of course, this drug spills inside her body, and turns her into a superhuman, as it opens up her cerebral capacity and she starts to access more and more of her brain powers, becoming nothing less than a combination of Jedi/goddess/witch who can do literally anything, at least before she suffers from the all consuming fate of her powers, meeting a similar end to her operating system character in Her, believe it or not.