An examination of the nature and the extent of the IRA's links with the German State prior to and during the Second World War. The two organisations were joined not by a mutual regard but by the desire to make war on the British. It was a liason characterisied mainly by lunacy, mistrust and poor communication. The film looks at the incompetence of IRA organisation and the interdepartmental rivalry of German bureaucracy. From Plan Kathleen to daring prison breaks, to round-ups of German spies and internment of IRA members The Swastika and the Shamrock is a picture of an idiosyncratic event in Irish history.