A mill on the banks of the River Dnieper. Natasha, the Miller’s daughter, is waiting for the
Prince she loves so passionately. The miller tells his daughter how to behave with a lover so that the latter will agree to marriage, or at least not stint in presenting rich gifts. Soon the Prince himself appears. Natasha is delighted at his arrival, but he is sad.
The Miller calls the peasants to comfort the guest with singing and dancing, though the latter remains unaffected. The Prince tells Natasha that they are soon to be parted. She guesses that he is planning to marry someone else. The Prince tries to buy his way out with extravagant presents and gives Natasha a necklace. The shattered Natasha informs the Prince that she is soon to become a mother. Promising not to abandon her and the child, the Prince departs. Natasha bitterly accuses her father for not preventing her liaison. In despair she plunges herself into the Dnieper.
A luxurious mansion. The Prince is celebrating his marriage amid great pomp and merriment. An ancient wedding ritual is underway. Suddenly a sad song can be heard about an abandoned girl who drowned herself. The guilty party was never unmasked. When the Prince attempts to kiss his young bride a woman’s scream can be heard. The banquet guests are left in disarray.
The Prince’s palace. The Princess is sad in her loneliness. The days when the Prince loved her have long since passed. Now she is increasingly left alone. Olga, the Princess’ friend, tries to distract her with a merry song. Having learned that the Prince plans to spend the night alone on the banks of the Dnieper, Olga and the Princess set out to look for him.
Night, the banks of the Dnieper. Twelve years have passed since the Prince last visited Natasha. The mill on the banks of the Dnieper have long been in ruins, but the Prince is still drawn here by some unseen force. The appearance of the unexpected visitor frightens the mermaids who have come to the surface to play in the moonlight. The Prince sadly recalls his former happiness. Suddenly a shabby old man in rags appears before him. It is the Miller, now insane and imagining himself to be a raven and the guardian of this place. He attacks the Prince. Hunters rush in and save their master.
The underwater palace of the mermaids on the bed of the Dnieper. Natasha has become queen of the mermaids. She sends them to the surface to play in the moonlight with her daughter Rusalochka with the order to meet her father on the shore and tell him that Natasha still loves him and is waiting for him. Left alone, she dreams of love and revenge on her rival in love.
The shore of the Dnieper. The Prince is once again at the miller's house; the Princess and Olga are also there and in the confusion they hide behind the ruins. Rusalochka approaches him from the waters and calls on him to follow her.
The Princess tries to stop her husband, but the Miller pushes him into the water. The mermaids take the body to their queen.