Paul's grandson, Dr Otto Brandt, visits his Aunt Alexandra in Spain where continual massacres erupt into civil war. Otto becomes entangled in the uprising led by General Prim against Spain's corrupt and incompetent government. The Spanish Queen Isabella flees to her French protectors. But France is eying an ever-strengthening German Federation with concern. If a member of the Prussian royal family accepts the vacant Spanish throne, the government of Napoleon III will react with hostility. General Prim sends Otto to Berlin via Paris. Worse, Bismarck sends him back along the same route. As the French economy totters war becomes inevitable. But Otto, a German, is trapped in Paris. Worse, he is trapped with thirty thousand other citizens of the German Federation. Elihu Washburne, the American Minister in Paris, works miracles. But where is Otto's sister?