An agent of the U.S. State Department dispatches the Hardys on an ultrasecret mission to track an international hit man in the Little Panaslava section of River Heights. But the Hardys don't know the identity of the assassin, or of his target, the exiled prince of Panaslava. Joined by Nancy Drew, Frank and Joe Hardy must slowly penetrate a wall of silence surrounding Little Panaslava--to make a shocking discovery.