In the near future, a young woman named Lucy leads a carefree life in Taipei, Taiwan. However, her existence takes a drastic turn when she gets caught in a dangerous situation after being kidnapped by a group of gangsters who force her to transport a powerful drug in her body. This narcotic, which is slowly released into her system, allows Lucy to access a much greater human brain potential than normal, awakening superhuman abilities.
As the drug is released, Lucy begins to experience a series of extraordinary changes. Her intelligence skyrockets, her perception of time and space transforms, and powers such as telekinesis, environmental manipulation, and the ability to recall any memory turn her into an almost divine entity. With the world at her feet, Lucy decides that she not only wants to survive but also to understand the vast complexity of humanity, life, and her own existence.
With the help of a professor specializing in neuroscience, Lucy embarks on a frantic race to stop her captors and discover the immensity of her abilities. The film tackles deep philosophical and scientific questions as Lucy struggles to control her new reality. With an explosive climax, it explores the question of what it means to be human and the limits of human potential, taking the viewer on a fascinating visual and cerebral journey.