When Franz presides over the German League, Bismatrck arrives late with a great Dane, a statue of the emperor it urinated on and the claim that his Prussian king should take over the presidency. Franz feels that's a  casus belli, but realizes he can't win a war, whoever starts it, without a much stronger army, which costs an obscene fortune. He intends to get a loan for it from napoleon III, who would cease to be an enemy to safeguard his 'invetsment'. To that end, the imperial couple travels to Biarritz, where he feels humiliated, but Andrassy suggests Ssi can win over the empress by showing trust by a personal request for a love nest. KIt nearly backfires, but the loan is awarded, yet Napoleon convinces Franz that Andrassy must be in league with Bismarck. Sisi must again interrupt their bliss since the birth of their heir to find out in Hungary if that country remains loyal.

A case, that remained a mystery for nearly thirty years. The desperate search of one brother for his sister. And the agony of those who are left behind by a chillingly brutal crime.