The Buryja Mill
Jenůfa waits anxiously to hear if her beloved Števa will be drafted, for she is carrying his child and her secret will soon be known. She is relieved to learn that he has not been called up and so can marry her before the pregnancy becomes obvious.
Števa’s jealous half-brother Laca secretly loves Jenůfa. A drunken Števa staggers in with some other recruits and breaks into a rowdy dance. Their behaviour incurs the disapproval of Jenůfa’s stepmother, the Kostelnička (not her name but her title – it means ‘village sacristan’) who tells Števa he can marry Jenůfa only after a year of abstaining from drink.
Left alone, Jenůfa begs Števa to marry her as soon as possible. They are interrupted and Števa runs off declaring that he will never abandon Jenůfa.
After Števa has left, Laca tries to incite Jenůfa’s anger against Števa; failing that, he impulsively slashes her cheek with a knife.
The worker Barena, who has been looking on, tells the others it was an accident, but the Foreman, who knows of Laca’s true feelings for Jenůfa, accuses Laca of hurting her deliberately.
The Kostelnička’s house, five months later
While everyone thinks Jenůfa has been sent away, the Kostelnička has hidden her away at home, where she has given birth to a boy. Though Jenůfa loves the child, the Kostelnička cannot bear the shame. Having secretly sent for Števa, the Kostelnička gives Jenůfa a sleeping draught. When Števa arrives the Kostelnička tells him about the baby and begs him to marry Jenůfa and acknowledge his son. Števa refuses: he is now engaged to Karolka, the Mayor’s daughter. Distraught, the Kostelnička turns to Laca, who is eager to marry Jenůfa. He is so upset to hear about the baby that the Kostelnička impulsively lies, claiming that the child is dead. Taking the baby, she heads for the freezing river to drown him. Jenůfa wakes, disoriented, just as the Kostelnička returns; the Kostelnička tells her she has been in a fever for two days during which the baby has died. She also tells her of Števa’s forthcoming marriage. Laca returns and offers himself to the Jenůfa. He insists that he loves Jenůfa despite everything and she agrees to become his wife.
Two months later
The marriage between Jenůfa and Laca is about to take place. Just as the couple are about to receive the Kostelnička’s blessing, a commotion outside interrupts the ceremony as the body of a baby has been found in the thawing river. Jenůfa realises this must be her own child.
Everyone now turns on Jenůfa, but the Kostelnička confesses her crime, begging the crowd to hold Jenůfa blameless. As the Kostelnička is led away to face her punishment, Jenůfa forgives her stepmother.