When Dr Lawrence Angelos experiments on animals fail, he finds the ideal substitute : Jobe Smith, a slow witted gardener - 'The Lawnmower Man'. Dr Angelo's goal is to benefit his human guinea pig and ultimately mankind itself. But evil lurks in the guise of 'The Shop', a shadowy group that seeks to use the technology to create an invincible war machine. When the experiments change the simple Lawnmower Man into a superhuman being, the stage is set for a Dr Jekyll and Mr Hyde struggle for the control of Jobe's mind and the future of the world.