"You are not fit to be a citizen of the United States," said a U.S. Representative to Werner Marx, German-Jewish refugee, distinguished sailor in the U.S. Navy during WWII, American Communist -- as he tried to have him de-naturalized in a hearing of the House Committee of UnAmerican Activities. House of UnAmerican Activities draws on a wealth of family archives (stills, home movies, documents, and a video interview with the filmmaker's mother), as the filmmaker searches for the father he never really knew and for the meaning of a troubled era.