The bodies of a murdered assassin and his wife are taken to NCIS after they end up dead in a car crash. It's soon discovered that the victims had reservations at a hotel where the United States Marine Corps birthday ball is scheduled to be held which means that someone at the ball could be a target. As such, Tony and Ziva go undercover, posing as the two married assassins and they attempt to discover who hired them but it's soon revealed that there's more to the case than meets the eye....