Director Luc Besson has given audiences some truly wonderful movies – Léon a prime example – but on the flip side he has also released some really good-looking but ultimately ridiculous films. The Fifth Element, anyone?

His latest offering is sci-fi action-thriller Lucy, and unfortunately, despite its tension-filled beginning, it also ends up going on a rather haphazard, vacant journey. Perversely enough, the fact that it stretches so far beyond any realms of reality means you are compelled to keep watching. 

Scarlett Johansson plays the title character, a student in Taipei who appears to have a penchant for making bad decisions. When we meet Lucy, her deadbeat boyfriend talks her into delivering a briefcase - well, she doesn't have much choice when he handcuffs it to her. Despite not having a clue about its contents, she is soon harangued into a narcotics-smuggling operation.

A bag of super-concentrated CPH4 is stitched into Lucy's stomach, but when the bag bursts inside her after a tussle with a lecherous heavy, she is loaded with superhuman powers (mind reading, the ability to manipulate matter and beings, to name a few) and, at the same time, drained of all human emotions.

Meanwhile, as Lucy's hitherto unrealised powers begin to take hold, world-famous neuroscientist Professor Norman (Morgan Freeman) is simultaneously lecturing about the human brain's potential in Paris. This is handy for the audience as it explains the theory Besson is basing the movie on: that humans only use a tiny percentage of their brains' capacity. Although it must be clearly stated this is not a scientific fact. 

With his premise in place, Besson punctuates the story with percentage values, representing the increase in Lucy's brain power over 24 hours, which she calculates is as long as she has left to live before her body goes into meltdown. With her life destroyed, Lucy goes on a mission: to track down the other drug mules so she can ingest more drugs, and to find Professor Norman, so that she can give him all the knowledge she has acquired. 

Her Korean enemies, led by Mr Jang (Min-sik Choi), barely slow Lucy down as the closer she gets to 100% brain capacity the less she has to try, brushing bad guys aside with not even a wave of her hand, just 'simple' mind control. Couple that with a pretty cool car chase and Besson manages to keep the movie moving, even if the dialogue is clunky and vacuous. 

Lucy is definitely worth a watch. Johansson is especially good, despite not having to push herself too much once Lucy becomes devoid of all emotions. That said, she really holds her own as an action star. The movie has a nice pace, looks sublime and kicks off with an engaging and what-could-be-superb story. However, things just fall apart once we hit the second act. 

Suzanne Byrne