Mrs. Elvsted arrives, terribly distressed, and tells the Tesmans that Lovborg never returned to the boarding house. She has heard some strange rumors, and she is afraid that something terrible might have happened to him. Brack enters and says that he heard about Rina's death, but that he has more "sad" news for them. Lovborg, he says, shot himself in the chest with a pistol and is lying "at the point of death." Mrs. Elvsted breaks down in despair, but Hedda merely questions Brack about the circumstances: where, she wants to know, did it happen, and is he certain that Lovborg shot himself in the chest, and not in the temple? Brack replies that he did indeed shoot himself in the breast, to which Hedda replies, "That's a good place too." Hedda then states that there is beauty in the act, shocking everyone. Hedda goes on: "Eilert Lovborg has closed his account with himself. Had the courage to do...what had to be done."
Mrs. Elvsted then reveals that Lovborg's book has been destroyed, which Brack finds suspicious. Mrs. Elvsted cries out that she wishes there was some way the book could be reconstructed, but then realizes that there is a way: it seems she still has in her possession all of the original notes. Tesman and Mrs. Elvsted announce that they will reconstruct the book together, and Tesman says that he will dedicate his life to the task. They both exit triumphantly.
Left alone with Brack, Hedda reveals that Lovborg's death has shown her that they are truly free, "because I know it's still possible to choose. Freewill! Still possible, and beautiful." Brack, however, tells Hedda in confidence that Lovborg didn't shoot himself: he was shot in Mademoiselle Diana's boudoir, and he is already dead. Hedda is stunned that he went back, but Brack adds that he entered Diana's raving about his "lost child" - which Brack assumes is a reference to his pocketbook, since Lovborg presumably tore his manuscript to pieces. Brack adds that Lovborg was fatally shot not in the chest, but rather in the bowels.
Brack then tells Hedda that the pistol with which Lovborg shot himself was Hedda's. He says that there will be an inquiry since the police are now in possession of the pistol, but as long as Brack doesn't say anything there is no way they will be able to trace it back to her. If he were to hint that the pistol might have been stolen, however, Hedda would be implicated in a terrible scandal and would have to appear in court to defend herself. Hedda, it appears, is wholly in Brack's power. "You...own me," she tells him, and exits the room to go lie down. A few moments later, a pistol goes off in the back room. Tesman runs in and calls out that Hedda has shot herself.
Hedda's singular goal throughout the play has been to prove that she is still in possession of free will. She believes that happiness, peace of mind, and purpose can be found in maintaining power over oneself despite all the pressures that the world places on an individual. As she manipulates those around her in an attempt to prove this to herself, she occasionally finds fleeting moments of peace, but as the last act hurtles towards its tragic conclusion, Hedda discovers that it she who spun the web in which she now finds herself trapped.
Several distinct moments precipitate Hedda's decision to take her own life. The first occurs when her husband and Mrs. Elvsted decide to resuscitate Lovborg's book. After she so deliberately destroyed Lovborg and Mrs. Elvsted's "baby", her husband will now join a new triangle in which she will have no part. Meanwhile, her husband has completely abandoned his own work for that of another man, and Hedda will be left with a permanent reminder of the man she couldn't love, and a mere shadow of the man whom she married.
Next, Brack tells Hedda that Lovborg's death wasn't so "beautiful" after all. Instead of shooting himself with Hedda's pistol, he went to Diana's boudoir, raved about the lost manuscript, and ended up getting shot in the stomach by someone else. His death was not only marked by a distinct lack of free will, but was also terribly painful. Hedda laments that everything she touches ends up being "sordid", but does not have the insight to see that it is her machinations that create these unfortunate circumstances.
Brack also reveals that he knows that it was Hedda's gun that killed Lovborg, and tells her that the only way she can avoid scandal is if he keeps quiet. Hedda has always been terrified of scandal, perhaps because it would tarnish her father's memory, or because it would limit her freedom to manipulate those around her while playing the part of the impartial observer. Even more, however, she is frightened of being beholden to another, of losing her free will entirely. She is faced with an impossible choice: throw herself on the mercy of society, or become Brack's "slave". Ultimately, of course, she realizes that there is a third option: death.
Brack never sets out any specific terms for his ownership of Hedda, but it certainly seems likely, given their earlier conversations, that a sexual element would be introduced at some point. Regardless, the mere idea of losing her free will is what finally leads Hedda to make her decision. She has bound herself into a corner from which she cannot escape. Hedda sees her life unspooling before her: she will remain wed to Tesman, who will in all likelihood fall in love with Mrs. Elvsted as they bond over their passion for their shared project. She will be prisoner to Judge Brack, who will "own" her for the rest of her life. She will bring a child into this toxic environment, and will most likely have to spend each and every day in the company of Aunt Julia. This, Hedda thinks, is what her life will be - drained of free will, drained of possibility - and so she gives herself the beautiful death she so badly wanted to see, convinced that perhaps it might set her free after all.