Scarlett Johansson and Morgan Freeman star in this sci-fi action thriller written and directed by Luc Besson. Johansson stars as the titular heroine who finds herself caught up in the dodgy dealings of the Taiwanese mob while living in Taipei. Forced into becoming a smuggler, she is drugged before a package is inserted into her stomach for safe transit.

Lucy is then severely beaten for protesting her situation which results in the package bursting inside her and leaking into her bloodstream. As the drug takes over her body, Lucy becomes capable of using a higher brain capacity than humans are naturally accustomed to which makes her able to use telekinesis and absorb knowledge rapidly. Meanwhile, neurological scientist Professor Norman (Freeman) takes an interest in Lucy's evolution as she takes revenge on those responsible for her extraordinary transformation and evades those who wish to harness her powers for their own ends.