Princess Odile who looks exactly like Odette.Siegfried is surprised and mistakes her for Odette. After she and the other royal princesses dance "Pas de six", Siegfried invites Odile to dance the "Grand pas de deux". lie announces his decision to marry her at once,which astonishes everyone. He swears he loves no one but Odile and sets her coronation ceremony as the wedding date. At that very moment, Odette arrives and Siegfried is now aware of his mistake. Odette looks at him sorrowfully and knows that his sacred oath has been broken. Rothbart is angry that Odette's appearance prevents Odile from becoming Empress, and he drives Odette back to the Silver Forest. He too disappears. Maria asks Siefried if this crisis can be the means bywhich he can become the new Emperor. Siegfried agrees and leaves the castle to findOdette, accompanied by Benno and the attendants.
Act4: The Silver Forest
Severely wounded, Odette is sent back to the lake where the princesses are confined.
On the evil island, they are almost strangled by rocks and trees. Siegfried arrives injured,having penetrated Rothbart's magic barrier. After saving Odette and the princesses, Siegfried begs Odettes's forgiveness. Rothbart is furious about this turn of events and tries to finish them off. Siegfried is beaten to the bottom of the lake. Odette, seeing him just about to die, figures out that the swan princesses will never get resqued if he dies, and she jumps into the lake. Not regarding Rothbart's anger and surprise, two at the bottom of the lake find each other and struggle to help themselves.
"What a humanity, what a love!" cries Rothbart, getting to know that the genuine love, which he has never believed in, truely exists on earth. He also finds his own magic,which has been protected by denying any love,is now vanishing, and he gasps to feel himself powerless. He utters and ruins altogether with the Silver Forest, when two in the lake get exhausted and stop moving.
Their cold bodies are pulled ashore on a golden boat. Benno, the soldiers, the swan princesses and the shadows unspelledfroni Rothbart, row the boat together. Then a stream of light comes onto two corpses. They see another bright beam in the sky pointing at the royal palace, and know that the soul of Siegfried and Odette are drawn above the heaven and the spirit supreme will be handed over in this land forever.
