- The stage directions introduce us to Sorin's farm. There's a lake in the distance with a small stage set up in front of it. It's just after sunset.
- The farm manager's daughter, Masha, and her suitor, Medvedenko, enter. He's a poor schoolteacher. She doesn't love him.
- Sorin enters with his nephew Konstantin. Sorin is middle-aged and sickly; he has headaches, asthma attacks, and rheumatism.
- Konstantin is a little nervous because he's about to premiere his play for the family. He's particularly afraid of his mother Arkadina's criticism. She's a famous actress and doesn't take well to other people's work.
- Nina enters. She's starring in Konstantin's play. They're in love with each other.
- Nina is anxious because the renowned writer Trigorin will be watching. Konstantin hates to hear the man's name mentioned; he's Arkadina's lover.
- Nina and Trigorin exit; Paulina and Dorn enter. She's the housekeeper, he's a country doctor. They're having an affair.
- Everyone enters in time to watch the play: Arkadina, Sorin, Trigorin, Medvedenko, Masha, and Shamrayev, the farm manager.
- Shamrayev, Arkadina, and Dorn argue about actors while Konstantin sets up.
- Arkadina is impatient for the play to begin, and when it does, she's totally disrespectful.
- Nina comes out dressed in white and gives a long, abstract monologue about the universal soul. Konstantin has put in some effects: two burning red eyes and a sulphur smell. His mother starts heckling the play and he calls it off. Konstantin storms out.
- Sorin scolds Arkadina for insulting her son.
- Nina emerges and bashfully meets Trigorin, her hero. They exchange a couple comments about creativity, but Arkadina doesn't really want them making nice.
- Nina goes home, while the others go inside.
- Dorn stays outside and is met by a miserable Konstantin. The doctor compliments the play—but has some advice for the playwright.
- Konstantin doesn't care; he just wants to find Nina.
- Masha enters, Konstantin leaves.
- Masha confesses to Dorn that she's in love with Konstantin.