The lake to which the title of the ballet refers is an enchanted mere, beside which a number of swans dance nightly by the light of the moon, in the semblance of young girls. The birds are the victims of the evil sorcery of a wicked genie of the place, from whose clutches they are powerless to escape. The opening scene discloses the wooded margin of the lake, the shining surface of which stretches before the eye to a dim further shore. The swans are seen upon the water, and while the orchestral prelude is in progress, they pass slowly across the gap in the trees, through which the shimmering lake is visible. At their head, more stately than her fellows, and distinguished by the tiny crown upon her head, swims the Queen Swan. The birds vanish. The ripples of their passage subside. Moonlight floods the still lake and its wooded bank. There enters a young man, armed for the chase, whose dress and mien proclaim him noble. Retainers follow him. They cast searching glances around, and scan the placid surface of the lake. But whatever it is they seek eludes their vigilance. A second young man joins them--the Prince of the realm--who has been benighted in the course of a hunting expedition. He, too, looks eagerly about him, but is no more successful in his quest than the companion who preceded him. They take counsel together, and in the very midst of their conference are startled by a distant apparition. They peer anxiously into the heart of the wood which fringes the lake’s edge, and obedient to the Prince’s order, all retire stealthily into hiding. The Prince himself, cross-bow in hand, follows his men. A moment later there enters a young maiden. She is fair to look upon, with a beauty that has a fatal quality of fascination. She is indeed the Queen Swan, wearing her temporary human guise, and only to be associated with her true form by the fillet of swan’s-down in her dark hair, and the snowy plumage with which her dress is adorned. This is the mysterious apparition which the Prince and his men have seen, lost, and now again discovered.