Maria Anna narrowly escapes being exposed – only to be cornered by the Queen, who mistakes her for Amadeus, whom she intends to seduce. Maria Anna stalls for time by playing a captivating piano piece until the Emperor finally intervenes and expels his sister from the court. The distraught Queen reveals the true reason for her return: Her husband, King Louis XVI, demands an heir after years of childlessness – fathered by a man of his choosing. But she has chosen Amadeus!

Alone and filled with remorse, Amadeus rejects the queen and begs Constance for forgiveness. He vows to bring Maria Anna back. Marie Antoinette, having no other choice, returns to France. Maria Anna's fiancé, Baron von Sonnenburg, recognizes her talent at their first meeting and agrees to break off the engagement. After an emotional conversation between Maria Anna and Amadeus, they free themselves from Leopold's control and vow to trust each other again.