It is late and the moon is high when Siegfried and his friends arrive at the lake where the swans have alighted. The men take no notice of a strange owl who stares at them malevolently from his perch in the ruins above the lake. The owl is in fact the sorcerer, Baron von Rothbart, who is jealously guarding his domain. Price Siegfried aims his crossbow at the flock. Suddenly one swan flies forward. He is fascinated and attempts to capture it. As the swan frantically tries to escape his grasp, she undergoes a startling transformation and, before his eyes, turns into the most beautiful woman Siegfried has ever seen. She tells him that her name is Princess Odette and, because of the spell cast on her years ago, she must remain a swan by day only to become human by the light of the moon. She implores Siegfried and his men to spare these swans, as they too are enchanted young women, and she is their queen. As the men retreat Odette disappears in to the mists and Siegfried goes off in search of her. Confident with the success of his manipulations, the sorcerer swoops down from his perch and bids the swan maidens to dance for him. Siegfried finds the beautiful Swan Queen, and just as he is about to swear his everlasting love, the very words that will free her, the sorcerer pulls Odette away with his magic. As the dawn rises, Odette reverts to her bird form, forgetting Siegfried and leaving him in the mist.
Excerpt from Ballet West synopsis 2019.