Act I The natural world
In the moonlight a group of Water Nymphs taunt their sister Rusalka. When the Water Spirit disrupts this game Rusalka confesses to him that she has fallen in love with a young Prince who visits the lake. She admits to the Water Spirit that she longs to leave the lake, to become visible, to acquire human form and feeling.
He tries to warn her that this is a bad idea, but realises that nothing can now hold her back. He tells her that the witch Ježibaba can perform the necessary spells to make her a woman. Rusalka calls on the moon to let her beloved know that she waits for him.
Ježibaba is dismayed by Rusalka’s request. However, she agrees to let Rusalka become a human being, but warns her that the price and conditions are severe. She will have all the attributes of a human being except speech. Furthermore, if she is rejected by her lover, then she will be an outcast – for ever caught between earth and water – and her lover will be condemned to eternal damnation. Rusalka blindly accepts everything and is transformed by Ježibaba.
As dawn breaks, Rusalka finds herself on land. The Prince is out hunting and chances upon Rusalka. He dismisses his retinue and fixates on Rusalka. Although Rusalka cannot speak to him, he is confident that his love will conquer all difficulties. He leads her away.
Act II The human world
Preparations are underway for Rusalka and the Prince’s wedding feast. The Kitchen Boy and Gamekeeper criticise and ridicule the Prince’s silent and mysterious bride. They fear that he has been bewitched. Yet it is still possible that the powerful Foreign Princess may rescue him from this unsuitable marriage.
The Prince is indeed already growing weary of Rusalka’s silence and timidity. The Foreign Princess wastes no opportunity to emphasise Rusalka’s lack of savoir faire, and begins to seduce the Prince. Rusalka is made to feel out of place and unwanted. Ignored and humiliated, Rusalka seeks the Water-Spirit’s help. He urges her to persist with the Prince, who is now openly courting the Princess. When Rusalka attempts to come between them, the Prince brutally rejects her. Now the conditions of Ježibaba’s spell begin to do their work. The Prince is overcome by madness and the Foreign Princess, appalled by the change in his personality, cruelly rejects him.
Interval of 20 minutes
Act III A desolate place
Rusalka returns to the lakeside. She is now an outcast from both land and water. Ježibaba offers her the possibility of returning to her original form if she murders the Prince, but Rusalka cannot bring herself to do this. She rejects bitterness and vengeance.
The Gamekeeper and the Kitchen Boy also seek out Ježibaba to ask for a spell to heal the Prince, who, since Rusalka’s departure, has fallen ill. At the suggestion that the blame lies with Rusalka, the Water Spirit appears and denounces the dishonesty of mankind. The Water Nymphs return to the lakeside and taunt the Gamekeeper. The Water Spirit is overcome by sorrow.
The Prince returns in search of Rusalka. She tells him that, because of his rejection, she is now a spirit whose kiss would prove fatal to a mortal. Nevertheless, he begs her to kiss him and bring him peace. He finds peace and consolation in death. Rusalka asks for mercy on his soul and forgives him. Rusalka transcends mortal life.