14-year-old Jason Shephard has one problem. He finds it very hard to tell the truth, which is slowly starting to lose the trust of his father. He is ordered to repeat the grade during the summer, if he is unable to get his essay in. When he is knocked off a bike by movie producer Marty Wolf, he accidentally gets his essay mixed in with Marty’s papers, leaving Jason’s story, ’Big Fat Liar’ behind. Sitting in the cinema, during the cinema, he makes a huge discovery. Marti Wolf has made a movie based on his essay. Now Jason, along with his best friend, Kaylee set off to retrieve his paper back and earn his dad’s trust back.