Charlie is a narcissist who is a dealer of new cars in Los Angeles, California. He hears of his father's death and is told that the vast majority of the estate has been left to Raymond, whom he cannot remember. Raymond is an autistic savant, who has an eidetic memory but is incapable of looking after himself. He has lived in an institution in Cincinnati, Ohio for about twenty years. Charlie drives Raymond to Las Vegas, Nevada where Raymond uses his skill at counting cards to win money in card games. They then go on to Los Angeles. During the journey, Charlie changes his feelings towards Raymond from being resentful to being caring and protective. Raymond lacks understanding of the world and requires 24 hour care, which Charlie cannot provide, so Raymond returns to his institution.