Simon Gruber is a fictional character known for his role in the action film series Die Hard. He is portrayed by actor Jeremy Irons in the third installment, titled Die Hard with a Vengeance. Gruber is depicted as a cunning and intelligent antagonist, seeking revenge against the protagonist, John McClane, played by Bruce Willis. In the film, Simon Gruber orchestrates a series of elaborate heists and challenges McClane and his partner, Zeus Carver, to solve riddles and complete dangerous tasks. His character is notable for his strategic thinking and ability to manipulate situations to his advantage, making him a memorable villain in the franchise.