Plot Summary

Lucy (Scarlett Johansson), a woman living an ordinary life, accidentally delivers a bag. In the process, she is kidnapped by Mr. Jang (Choi Min-sik), a master of the underworld. She is shipped all over the world with an unknown blue synthetic drug (C.P.H.4) in the stomach of several people who have been kidnapped by Mr. Jang like herself. Lucy goes to Taiwan. There, an external shock causes her stomach to explode. The accident allows Lucy to use more than 20% of her brain, unlike the average person. And she continues to increase the capacity of her brain by multiplying cells. While tracking past kidnappers to find C.P.H.4's whereabouts, Lucy seeks out a neurologist (Morgan Freeman) who can help her.