In a world where no one can lie, Mark Bellison is a down-on-his-luck screenwriter who works at a movie studio. He’s about to be fired from his job because his scripts are unoriginal and unsuccessful. He’s also facing eviction and rejection by his love interest, Anna McDoogles.
During a date with Anna, Mark is served an eviction notice, and she rejects him because of his lack of wealth and genetic fitness. Mark hits rock bottom when he’s fired from his job. In a moment of desperation, he lies to the bank clerk about having $800 in his bank account. To his surprise, the lie works, and he’s able to withdraw money he doesn’t have.
Mark realizes that he’s the first person in the world to lie, and he uses his newfound ability to improve his life and help others. He tells his dying mother comforting lies about an afterlife, which brings her peace. He also invents the concept of religion, claiming to have spoken to a “Man in the Sky” who gives him commandments written on pizza boxes.
Mark’s lies about the afterlife and the Man in the Sky spread quickly and become the foundation of a new religion that provides comfort and hope to people. However, Mark’s success attracts the attention of the authorities, who want to use his ability to lie for their own purposes.
Mark becomes disillusioned with his own lies and the way people use them for personal gain. He tries to confess the truth to the world, but he’s interrupted by Anna, who confesses her love for him. Mark realizes that even though lying has caused him trouble, it has also brought him closer to Anna and helped him find love and happiness.
In the end, Mark chooses to continue lying to protect the feelings of others and maintain social order. He and Anna start a relationship, and Mark becomes a famous figure in society, revered for his ability to give people hope and comfort through his lies. The film ends with Mark and Anna walking hand in hand, contemplating their future together in this new world of truth and lies.