Act I A meadow by a lake, surrounded by a forest
In the moonlight, three wood nymphs taunt the Water Spirit. The water nymph Rusalka confesses to the Water Spirit 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 agrees to let Rusalka walk on land, but the price and conditions are severe. She will have all the attributes of womanhood except speech. Furthermore, if she is rejected by her lover, then she will be an outcast – forever caught between earth and water – and her lover will be condemned to eternal damnation. Rusalka blindly accepts everything and, once the spell is pronounced, prepares to meet the Prince.
As dawn breaks, the Prince is drawn to the lake. He dismisses his retinue and waits by the waterside. Rusalka appears and, although she cannot speak to him, he is confident that his love will conquer all difficulties. He leads her to his castle.
Act II The Prince’s castle
Preparations are underway for Rusalka and the Prince’s wedding feast. Below stairs, the kitchen boy and gamekeeper criticise the Prince’s silent and mysterious bride. They fear that he has been bewitched. Yet it is still possible that the Foreign Princess visiting the castle may rescue him from this unsuitable marriage.
The Prince is indeed already growing weary of Rusalka’s silence and timidity. The Princess wastes no opportunity to emphasise Rusalka’s lack of savoir faire, and as the ball progresses the Prince spends more and more time in her company. 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.
Act III The meadow by the lake
Rusalka returns to the lakeside. She is now an outcast from both land and water. Jezibaba offers her the possibility of returning to her original form if she murders the Prince, but Rusalka cannot bring herself to do this.
The gamekeeper and the kitchen boy also seek out Jezibaba 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. When the wood nymphs return to the lakeside, he warns them of Rusalka’s fate.
The Prince returns to the lake 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. Rusalka asks for mercy on his soul and, accepting her own fate, disappears beneath the waters of the lake.