Percy Jackson (Logan Lerman) is a somewhat misfit student who doesn't feel as if he fits in with anyone other than his best friend Grover (Brandon T. Jackson). His life takes a very unexpected turn when he walks into the New Roman and Greek Art Gallery as part of a school field trip. It is revealed that Percy is a descendant of Poseidon, Grover is actually a satyr (half human, half goat) and his protector - and one of his teachers - is actually a centaur. To make things more complicated, Zeus' lightning bolt has been stolen and Percy is the prime suspect. Percy is taken to a camp to learn to use his powers and at the same time his mother is taken prisoner by Hades. When Percy hears this news, he leaves the camp, along with Grover and Annabeth (Alexandra Daddario) to rescue his mother. However, they encounter Medusa (Uma Thurman) standing in their way, among other threats.