In a small village in Ukraine, village girls prepare for the Green Holiday, decorating houses with trees and herbs, to ward off the water spirits, the rusalky. As the girls decorate, women warn them of the dangerous rusalky. The boys tease them for their superstitious nature. To make amends, the boys invite the girls to dance. After they dance, they ride off in a wagon. Unfortunately, the wagon is full and one girl, Khrystia, falls from it. The others depart, unaware of Khrystia’s absence.
Lileya, a rusalka, emerges from the lakeshore and sees the fallen Khrystia. The rusalka is young, interested and curious. She and other rusalky begin to dance with Khrystia. The frenzy culminates around Khrystia, who is quickly encircled. The sprites begin to rob Khrystia of her ribbons, vinok, and apron. The young rusalka dresses in Khrystia’s beautiful clothes.
The girls and boys return from their wagon ride and begin to dance. One boy, Andrij, is without a partner; fellow villagers give him a rusalka-scarecrow to dance with. The villagers taunt and mock him, leaving him alone, sad and frustrated. Lileya watches Andrij from a distance and becomes enchanted by him. She surprises him and they join in a mystical duet.
In the midst of this beautiful dance, the rusalky return with Khrystia, preparing to drown her, covering her in leaves and grasses. Lileya and Andrij rescue Khrystia and Lileya is pulled back with the rusalky. Khrystia is unconscious on the lakeshore and Lileya has disappeared. Andrij searches for his love. Distraught, he collapses with grief.
Rusalky emerge from the river and surround Andrij. At first, Andrij is mystified by the rusalky, but he quickly realizes how dangerous they are. He sees Lileya and she comes to his rescue before the rusalky can tickle him to death. Concerned for both Andrij and Khrystia, Lileya tries to save them by showing them that Khrystia is fleeing. The rusalky attempt to catch Khrystia, but because of Lileya’s helpful ruse, she is able to escape their trap.
Khrystia runs in from the lakeshore to the village and explains to the villagers that she was robbed by the rusalky. At that moment, she sees Lileya with Andrij. Angry, she explains that this new “girl” is really the dangerous rusalka who stole her clothes. The villagers believe her and are angry with Lileya. Khrystia is not convinced that this rusalka has good, innocent intentions. She comes from behind the rusalka to torment her with herbs. Overcome with fear and devastation, Lileya collapses to the floor. Andrij defends the rusalka, taking her in his arms and kissing her. With his love, the rusalka comes to life.
The herbs are now powerless against the rusalka because Andrij’s love has transformed her. The villagers turn on Khrystia, mocking her and laughing at her. Devastated, she leaves the village.
Andrij proposes to Lileya, and once again they dance. The villagers, rejoicing in this marriage, celebrate with a hopak!