Jonathan Mardukas is a fictional character from the 1990 film Midnight Run, directed by Martin Brest. He is portrayed by actor Charles Grodin and is a former mob accountant who has embezzled money from a crime boss. Mardukas becomes the target of bounty hunters and law enforcement due to his knowledge of the mob's illegal activities. In the film, Mardukas is pursued by a bounty hunter named Jack Walsh, played by Robert De Niro. The story follows their journey across the United States as they encounter various challenges and develop an unexpected bond. Mardukas' character is known for his intelligence, wit, and ability to navigate dangerous situations.