All is despondent and gloomy in Kashchey's kingdom. It is mid-autumn. The Princess of Untold Beauty languishes in her confinement, forcibly separated from her beloved Ivan-Tsarevich ("Days without light, sleepless nights, like wintry clouds they pass in an unchanging course..."). Kashchey enters. The Princess begs that the evil wizard gives her a chance to see her betrothed. Kashchey gives the Princess a magic mirror in which she sees Kashchey's daughter, and next to her is Ivan-Tsarevich. Kashchey also looks into the mirror and sees his own death there. Frightened, he sends Storm-Wind to his daughter to discover whether she still keeps his death close to her. The Princess asks Storm-Wind to reveal her intended and to tell him hwo she languishes in captivity. Storm-Wind sets out for the Far-Away Kingdom where Kashcheyevna lives.
Kashchey speaks of the secret of his immortality which lies in his daughter's tears – until Kashcheyevna cries nothing can threaten the wizard ("I have discovered the mystery of nature: I have found the gift of immortality"). Then he calls the Princess and asks her to sing him a lullaby, but she does not wish to enter the tower. Vengeful, Kashchey calls forth a snow-storm and blizzard on his kingdom.
A rocky island by the sea. In the moonlight, Kashcheyevna approaches the sea with a cup containing a magical elixir that she offers to young knights before killing them ("Night has fallen. The wind has dropped. Sweet-smelling darkness all around, and the wicked waves roll in more strongly...). Ivan-Tsarevich appears. The beauty of nature makes him think once more with nostalgia about the Princess ("Hark, oh night and sweet-smelling garden, night waves, stars and flower!"). Kashcheyevna offers the Tsarevich the goblet. He drains it and falls under the power of Kashcheyevna's magic charms. The wizard's daughter is also attracted by the knight ("A wave of passion shall carry us in a golden boat, through a sea of sweet dreams."). The Tsarevich falls asleep and Kashcheyevna holds a sword above him, but in a moment of indecision she hesitates. Suddenly Kashchei's Storm-Wind herald appears. Storm-Wind dispels the witch's charms – upon wakening, Ivan-Tarevich sets of with Storm-Wind for Kashchei's kingdom. Kashcheyevna also races there.
Kashchei is asleep in his tower, while the Princess, sitting on the porch, sings an evil lullaby to him ("Hush, hush, grey-headed Kashchey, evil immortal!"). Storm-Wind brings Ivan-Tsarevich to Kashchey's kingdom. The lovers greet each other in delight. ("The hour of separation has passed, my beloved friend is with me."). The Tsarevich lures the Princess after him to her freedom, but on the way they are stopped by Kashcheyevna. Love has erupted in her cold heart. She begs the Tsarevich to remain with her, promising to grant the Princess freedom. Moved by a sudden feeling of compassion, the Princess kisses Kashcheyevna. Kashcheyevna's heart softens, and tears appear in her eyes ("My eyes weep tears, for the first time. Like the dew on a fragrant flower, the tears refresh my heart..."). Kasheyevna is transformed into a beautiful weeping willow, and as she weeps so Kashchey's death comes.
Unseen voices announce the death of Kashchei. Storm-Wind throws the gates open wide – from the kingdom of death they may now travel the road to the kingdom of love and happiness.