Secret agent Major William Morgan is an American secret agent in 1955, when the cold war against communinism was heating up. Each episode began with this statement: A Warning to all enemies of America at home and abroad who are planning acts of aggression: This is the story of the gallant men and women who penetrated and are still penetrating enemy lines to get secret information necessary for the defense of the United States. This is the story of one of our nation's mightiest weapons past, present and future if necessary - the American intelligence services. Each episode ended with: "There is and will be, no rest for those engaged in the war against oppression. Let all agressors beware!" The show was filmed in Amsterdam and sold to television stations as an independent syndicated program. Although many more episodes were created, only the first four are known to exist today.