And I thought the most scientifically inaccurate movie ever made was “Cloudy With a Chance of Meatballs.” Never underestimate Luc Besson, whose sci-fi tinged thriller “Lucy” achieves a new high score on the science violation index. In every scene the French action maestro beats physics, biology and common sense to a pulp.

Scarlett Johansson plays Lucy, an unwilling drug mule who attains superhuman abilities when a packet of synthesized uppers in her stomach ruptures. The drug allows her to harness the entire capacity of her brain. The film, repeating a widespread myth, asserts that the rest of us muddle through on just 10 percent of our cranial horsepower. Besson’s target audience seems to be somewhere lower than that.

Once Lucy’s whirlwind of mental energy is released, she is able to absorb other languages instantly, give herself a chameleon-like blonde-to-brunette makeover, and telekinetically clout her enemies at a distance. She can comprehend all the biological processes in a person’s body with an MRI-like hug, monitor a city’s worth of cellphone calls in her head, and travel through time. Brainsmarts! Basically, she’s a half a dozen X-Men in a miniskirt and stiletto heels.

With great power come enormous side effects. Unless Lucy keeps taking the designer drug, she gets uncontrollable fidgets and literally dissolves into a light show of neon space rays.

The villain who sewed the packet into her stomach, ultra-evil Mr. Jiang (the fine South Korean actor Choi Min-sik) would rather send a platoon of hit men after her than share his supply. Lucy hurts the murderous Jiang enough to make him furious but allows him to live. It doesn’t take half a brain to know that’s a dumb move. Then she partners with a tough Paris police detective (Amr Waked), who’s basically on hand to gape at her miracles and provide a halfhearted romantic subplot. The bad guy attacks again and again, but there’s no urgency in this deity vs. gangster mismatch.

Please don’t think I’m demanding too much plausibility from a fantasy film. I just saw a movie about a society of talking apes and I was fine with it. That movie established its premise, set forth the laws of its fictional universe, and stuck to them. At no point did a troop of flying monkeys with death rays appear just because somebody thought that would be neat. The movie worked because, while preposterous, it was consistent. Every scene gave you another reason to buy into its alternate dimension. Every egregious scene in “Lucy” defies you to ignore how ludicrous it is.

And yet “Lucy” has its sideline charms. It’s a glossy production that virtually drips visual style. It’s energetic, in a funhouse-crazy way. Before the action begins to boil, Besson tosses in numerous clips from magicians’ parlor tricks and nature documentaries to playful effect. Besson being Besson, the wildlife vignettes show animals rutting. Morgan Freeman plays a renowned brain theorist, patiently explaining the gibberish plot as if he were still on “Sesame Street.” And for the first quarter hour, when Johansson’s character is a normal woman in frightening circumstances, she’s very effective.

Once she attains cosmic consciousness, however, she goes blank-faced and dead-eyed as a mannequin. She even speaks in a droning monotone robo-voice far duller than the one she used as a hyperintelligent app in “Her.” Like its dissolving heroine, “Lucy” reaches to a finale that just sort of drifts apart and floats away.