Mrs. Elvstead, a pretty, delicate woman, arrives at the house, having left some flowers and a calling card there earlier. It is immediately apparent that she is distraught, but is hesitant to reveal the source of her dismay. Finally, she reveals that she is at her wit's end because Eilert Lovborg has recently arrived in town, and that she fears the town will be full of "temptations" for him. Lovborg used to be the tutor to Mrs. Elvsted's step-children, and recently wrote a bestselling book. He was a model of sobriety while he was living with the Elvsteds, but Mrs. Elvsted is concerned that living in the city will prove too much for him. She begs Tesman to keep an eye on Lovborg, as he will certainly seek out his old friend. Hedda tells Tesman that he should invite Lovborg over to visit (and urges him to write a "long" letter), and Tesman goes out of the room to compose the invitation.
As soon as Tesman leaves, Hedda tells Mrs. Elvsted to explain what's really happening. Mrs. Elvsted is reluctant, saying that Hedda used to torment her viciously at school, but Hedda dismisses the incidents as mere childhood play. She treats Mrs. Elvstead with remarkable affection, urging her to call her "Hedda" and looking at her with compassion in her eyes. Slowly, Mrs. Evlsted opens up and reveals that she never had a happy marriage - indeed, that her husband is "repellant" to her - and that when Eilert Lovborg began to tutor her husband's children, they developed a close relationship. Mrs. Elvsted claims she saved him from vice, and that in return, Lovborg taught her a great many things. She also says that they worked on his book together. But Mrs. Elvsted adds that she's afraid there's another woman in his heart - a woman he only spoke of once. She recalls that Lovborg said that when he and this woman parted, the woman threatened to shoot him with a pistol.
Mrs. Elvsted leaves, and Judge Brack enters the house. Brack and Tesman sit down to talk, and Brack promptly brings up the subject of Lovborg's return. Brack subtly implies that because of Lovborg's influence in the town, he may receive the professorship that Tesman's been expecting. Brack leaves, and Tesman tells Hedda that since the professorship is in doubt, they need to be more frugal. Hedda drolly replies that she at least has one thing left to amuse her - her father's pistols. As Hedda leaves the room, Tesman runs after her, pleading with her to leave the dangerous weapons alone.
The plot thickens considerably in the second half of the first act, offering more information that will assuredly pay off in the play's climax. First, Brack sets up the implied duel between Jorgen and Lovborg over the professorship that is essential to Tesman's financial solvency - and thus crucial for the success of his marriage, since Hedda comes with certain expectations about her standard of living. Second, Mrs. Evlsted reveals that though she and Lovborg have grown close, she is afraid a woman stands between them - a woman who shoots pistols. The final image of the first act is of Hedda leaving Tesman to go shoot her father's pistols, thus revealing that not only does Lovborg stand between Tesman and the professorship, but also between Tesman and Hedda.
Readers gain a fuller understanding of Hedda's character in the second section of the act. For example, Mrs. Elvsted tells Hedda that she cannot confide in her because of the way Hedda treated her at school (threatening to burn her hair, tormenting her), but Hedda calmly dismisses it as "talk" and manipulates Mrs. Elvsted into confiding in her. As readers, we already sense that Mrs. Elvsted is slowly becoming wrapped up in a snake's coils, but Hedda is the play's protagonist, so more information is needed before we can completely abandon our sympathies. Later, when Hedda encourages Tesman to invite Lovborg over in order to get him out of the room, we have the same reaction: curiosity as to what Hedda is planning, but continued refusal to wholly implicate her as the villain.
One of the key moments comes at the end of the act when Tesman suggests that the loss of the professorship would mean the end of Hedda's extravagant lifestyle: she would have to curb her spending for the sake of the marriage. Hedda promptly replies that she still has her pistols to amuse her. The question, of course, is who the pistol would be pointed at: Tesman, herself, or Lovborg?
At this point, it is perfectly clear that Hedda is miserable in her marriage, and yet completely responsible for her own misery - she not only willingly married Tesman, but is seemingly pregnant, and we have no idea why she's allowed either situation to come to pass. As General Gabler's daughter, we assume she had other options for marriage, and yet there is the strange sense that she forecasts her own doom - that she senses in her an alien nature that cannot exist in harmony with the world. She must cause chaos, or she must die.
Indeed, Hedda has set designs into place that we cannot yet quite understand - simply because we have yet to fully decode the target of her rage. If it is an internal conflict that drives her, then she is strangely devoid of self-loathing. If it is anger at the world, then she is curiously passive-aggressive. As we move into Act II, we will achieve a better understanding of how Hedda's state of mind motivates her actions.