Charlie (Tom Cruise), a young businessman who abandoned his family to pursue a career in business, returns home to attend his father’s funeral with the hope of inheriting a $3 million fortune. However, to his surprise, his father leaves the entire sum to someone he has never heard of before. Following the clues he has, Charlie discovers that the “lucky recipient” is actually a mentally challenged patient named Raymond (Dustin Hoffman). Even more peculiar, Raymond turns out to be Charlie’s long-lost brother, whom he had never known about. Determined to reclaim half of the money, Charlie comes up with a plan to kidnap Raymond and bring him back to Los Angeles. However, everything starts to change as Charlie begins to understand his brother better – a patient with autism who possesses an exceptional memory, able to remember vast amounts of knowledge in various fields, but is naive, easily frightened, and incredibly innocent, with heartwarming memories of their family. Initially driven by the desire to take the large sum of money, Charlie gradually has a change of heart during the time spent with his brother.