A Doll's House opens as Nora Helmer returns from Christmas shopping. Her husband Torvald comes out of his study to tease with her. They discuss how their finances will improve now that Torvald has a new job as the vice president of the bank. Torvald expresses his horror of debt. Nora behaves childishly, and he enjoys treating her like a child to be instructed and indulged.
Soon Christine Linde, an old friend of Nora's, arrives at their home. She is a childless widow who is moving back to the city. Her husband left her no money, so she has tried different kinds of work and now hopes to find some work that is not too strenuous. Nora confides to Christine that she once secretly borrowed money from a disgraced lawyer, Nils Krogstad, to save Torvald's life when he was very ill, but she has not told him in order to protect his pride. She told everyone that the money came from her father, who died at about the same time. She has been repaying the debt from her housekeeping budget and also from some work she got copying papers by hand, which she did secretly in her room, and took pride in her ability to earn money "as if she were a man." Torvald's new job promises to finally liberate her from this debt.
Nora asks Torvald to give Christine a position as a secretary in the bank, and he agrees, as she has experience in bookkeeping. They leave the house together.
Krogstad arrives and tells Nora that he is worried he will be fired. He asks her to help him keep his job and says that he will fight desperately to keep it. Nora is reluctant to commit to helping him, so Krogstad reveals that he knows she committed forgery on the bond she signed for her loan from him. As a woman, she needed an adult male co-signer, so she said she would have her father do so. However the signature is dated three days after his death, which suggests that it is a forgery. Nora admits that she did forge the signature, so as to spare her dying father further worry about her (she was pregnant, poor, and had a seriously ill husband). Krogstad explains that the forgery betrayed his trust and is also a serious crime. If he told others about it, her reputation would be ruined, as was his after a similar "indiscretion," even though he was never prosecuted. He implies that what he did was in order to provide for his sick wife, who later died.