Franz breaks with Count Andrassy and, at the last minute, risks the support of the Hungarians in the impending war. While Sisi has to prove herself as a ruler alone in Vienna, her heart is with Franz and Andrassy on the battlefield.

The war has left deep wounds. Franz does not let Sisi get close to him and sends her back to Hungary. She does not yet suspect that this could be a farewell forever, but deeply hurt Sisi decides to go.

The proclamation of the republic and the fall of Napoleon III also lead to unrest in Vienna. Franz therefore decides to start his son Rudolf's military training earlier. At the same time, he orders Grünne to mingle incognito with the protesting workers in order to find out who their leader is. Sisi is unable to protect her sensitive son from the army and decides to free him on her own.