The next evening, it is time for Prince Siegfried to choose a bride. The Queen has arranged for princesses from many lands to introduce themselves at a courtly ball, all hoping to catch the Prince’s eye. The court jester keeps the atmosphere light with his tricks and tumbles. Thinking only of Odette, Siegfried is not interested in the other women or the evening’s entertainment. When his mother commands him to choose a bride, Siegfried keeps his vow to Odette, accepting no one.  

Suddenly, trumpets sound, announcing the arrival of new guests. Von Rothbart appears disguised as a noble with his daughter Odile. She has been bewitched to look like Odette. Siegfried is transfixed by the impostor. As Odile dances with Siegfried, Odette is seen in the far window of the castle trying to warn Siegfried of this deception. Siegfried, thinking that Odile is Odette, swears his love and promises to marry her. When the triumphant Von Rothbart reveals himself and Odile for who they truly are, Siegfried realizes that he has broken his oath to Odette. He has doomed her to forever remain a swan. Odette flees, distraught, as her swan maidens flood the castle in a moment of utter chaos. Guilt-ridden and despairing, Siegfried rushes after Odette, following her out from the castle and to the lake.