A citizen of Saudi Arabia dies in an explosion of a car aboard the Naval Air Station, Patuxent River, near Lexington Park, Maryland, between Chesapeake Bay and the Potomac River; the victim was the driver of a limo serving a Saudi prince, who was at Pax River for an advanced USN-USMC training program for pilots. Gibbs and company investigate; Gibbs assumes that someone had intended the bomb for the prince, so Gibbs also provides protection to the reluctant prince. Tony's father, Senior, arrives at the office to visit Junior; he promptly shows himself to be a ladies' man; he reveals that he has done business with the father of the subject prince. The prince's brother and their father also show up. After McGee and Abby find a key piece, the gang figure out the puzzle; Tony learns about his father, his history, and his situation.