We learn that Paulina loves Dorn and that they are involved in a romantic relationship, but he is mostly apathetic about her affection. Paulina is jealous of the attention Irina Arkadina receives from the men, especially Dorn, because Arkadina is an actress. Dorn prides himself on his life of romances and Paulina hypothesizes that he still receives attention from women because he is in good shape. Dorn disagrees. He thinks it is because he is a doctor. Paulina tries a romantic move on Dorn but is interrupted by the arriving guests.
Dorn, Shamrayev, and Arkadina argue passionately about the merits of famous actors in Russia and the quality of their contemporary theater. Dorn says that actors in smaller roles have improved. Arkadina asks Treplev when the play will start and he snaps back at her to be patient. Arkadina shows off to the group by reciting lines of Gertrude in Shakespeare's play, Hamlet. Treplev responds by reciting lines of Hamlet in Hamlet, back to her. His lines compare Arkadina's relationship with Trigorin to Gertrude's tainted relationship with Claudius. Treplev's play begins, and Nina takes the stage. She recites a long monologue about the universe, a universal soul and man's place on earth. The qualities of the play are very abstract and symbolic, and Nina's speech is representational. Instead of creating action, she paints an impression, almost like a word painting of an idea with her speech. Arkadina rudely interrupts the performance several times by talking out loud to her friends in the audience. She does not try to understand or appreciate what Treplev is attempting to do. When a special effect of red lights in the form of two eyes and the smell of sulpher rises in a cloud from the stage, Arkadina makes such a fuss that Treplev ends the play and closes the curtain. He runs off.
Sorin scolds Arkadina for her insensitivity to Treplev's ego. She denies understanding how important the play was to her son and belittles the new forms of the theater that are emerging. Nina comes out from behind the curtain, and the audience members, including Arkadina, compliment her beauty and talent. Masha eagerly goes off to find Treplev. Arkadina hears singing in the distance. With nostalgia, she tells Trigorin about the way life in the country was full of love affairs, and socializing with music and dancing years ago when she and Dorn were desirable youth.
Nina meets Trigorin for the first time. Arkadina laughs at Nina's awe of Trigorin's role as a creator. Nina leaves in a hurry though she wants to stay. Arkadina mentions Nina's unfortunate circumstances. Nina's late mother's fortune was left only to her father, and he left the money to his new wife, so Nina lost her inheritance. Everyone leaves the area but Dorn. Treplev comes back. Dorn compliments his work. He tells Treplev that he liked the play. Dorn gives Treplev advice about writing, saying, "Everything you write has to have a clear, concise, central idea. You have to be aware of what you're writing otherwise you'll you'll lose your way, and your talent will destroy you." Treplev desperately desires Nina but learns that she has already left. He runs off again. Masha takes a pinch of snuff. Dorn criticizes her. She admits to him that she is in love with Treplev. Dorn sighs over the abundance of unrequited love in his presence.
We meet Dorn, the country doctor, and one of Chekhov's few doctor characters. He does not say or do a lot, but we learn several things about his character that allow us to infer some things about his role in the play and about Chekhov as well. Dorn is casual and laid-back. His conversation with Paulina, though passionate on her end, remains aloof and unaffected on Dorn's part. Though Paulina seethes with jealousy and insecurity, Dorn does nothing to reassure her or boost her confidence, nor does he insult or put her down. Dorn displays himself as a neutral force in the play. Though involved in the affairs and passions of the characters around him, Dorn stays a distance away from the action, allowing himself a position from which he can take part without taking any personal risk. Dorn is similar to Trigorin in this respect, but different in a significant manner. Though Trigorin also stands aloof to most of the action around him, he only involves himself personally when he has something at risk. Trigorin is inherently selfish in this way whereas Dorn will stick his neck out for others. For instance, when Dorn tells Treplev that he liked his play though the others did not, he conveys his nature as a compassionate man who sympathizes with others' struggles, though he does not become affected emotionally by their suffering.
Dorn's personality may be a result of how Chekhov perceives the role of the doctor in country life. A doctor in a rural district of Russia such as the one Dorn and Chekhov worked would witness thousands of ill people with tragic stories, difficult lives, and deaths. In order to survive peacefully without succumbing to the sadness of the work, a doctor would need to keep a balanced perspective on the lives of those around him by providing advice when helpful, but otherwise, remaining uninvolved in the matters of the heart. As a neutral, compassionate figure, Dorn represents Chekhov's role as playwright and ourselves as audience. One of the triumphs of Chekhov's writing in The Seagull is his unbiased depiction of the characters. The story is not easily divided into good vs. evil or hero vs. villain. Chekhov attempts to portray people as they are in real life, a little good and a little bad, somewhat right, and somewhat wrong.
Critics disagree on the significance of Chekhov's play-within-a-play written by Treplev in The Seagull. Some say the play Nina begins to perform has merits in its own right as a significant contribution to modern playwriting. Far more believe this little play with big ideas allows Chekhov to poke fun at his own grand ideas at changing the form of modern plays and the symbolist movement of which his plays took their inspiration from and contributed to greatly.
Arkadina displays her lack of compassion and childish competitiveness hen she prevents her son, Treplev's play from having a fair chance at performing, uninterrupted. We also witness Treplev's overactive sensitivity to needing his mother's approval when he stops the show on her account and runs away. This establishes what consists of the main conflict in the play.
Dorn's role as a neutral, central, compassionate figure who knows all, but does not effect the action, reiterates itself when, at the close of Act One, Treplev confides his love for Nina to Dorn and Masha reveals her love for Treplev to Dorn.