Act one of the play A Doll House by Henrik Ibsen takes place in the living room of the Helmer family who lives in Norway during the Christmas season in the 1800's. Torvald Helmer is a lawyer who is married to Nora, and they have three small children. They live in a big house with assistants, such as a nurse, Anne-Marie, and a housemaid. The play opens with the couple having a conversation about money and Christmas. Nora is excited that Torvald is receiving a promotion so that they will have more to spend on gifts this year. Torvald chastises her for always wanting more money, comparing her to her father, and wondering where it goes. Many lines in this conversation foreshadow things that the audience will learn about Nora later in the play. Throughout the conversation Torvald calls Nora many pet names, most of which refer to birds. He never uses her name.

At some point they are interrupted by Kristine Linde appearing at the door. She is an old friend of Nora's who hasn't seen her in many years. Mrs. Linde describes how she had to marry her husband many years earlier to help support her ailing mother and her two younger brothers. Three years ago her husband passed away, so she had to find jobs to support herself. Since then her mother passed on, and her brothers are able to support themselves, so she is mostly lonely although still looking for a consistent job. Nora tells Kristine about how her husband recently received a promotion to bank manager and how she thinks she can convince Torvald to give Kristine a job. Then Nora confesses a secret to Kristine that she has never told anyone. She explains how when they were first married, Torvald had to work very hard, and he became sick. The doctor suggested they go south, so Nora told him that she borrowed the money from her father who died shortly thereafter. They lived in Italy for a year while Nora cared for Torvald and their newborn son. What her husband doesn't know is that Nora actually took out a loan that she's been paying back ever since. Nora doesn't do much work, aside from the occasional sewing or copying of documents, so it has been hard for her to pay the interest on the loan. She's had to use her allowance from her husband frugally to save a little each month. It has been very stressful for her, but it was also empowering that she borrowed this money and took charge like a man.

During their conversation Dr. Rank, a friend of the family, has been talking with Torvald. He comes in and meets Mrs. Linde. Then Nora tells her husband that Kristine has come looking for secretarial work, and does he think he could find her a job? Torvald says he thinks he can. Kristine leaves pleased, and Dr. Rank follows. Another gentleman has come in, Krogstad, who will be working under Torvald at the bank. After Torvald leaves, Nora plays with her children a bit before Krogstad returns to the front door. Nora is upset to see him and sends the children away.

Krogstad has come to talk to Nora about the money he loaned her all those years ago. He is worried that when Torvald hires Kristine, he will lose his job. He needs that job because he has a somewhat tarnished reputation and will have a hard time finding another job. Nora doesn't care about his situation. She knows that her husband will soon be able to pay off the remainder of the loan. However, Krogstad points out that when he agreed to lend her the money, it was under the assumption that her father would co-sign, but when he checked the date of her father's signature on the document, he realized it was dated three days after her father died. Nora admits that she forged her father's signature, which means she committed fraud. He threatens to tell if she does not help him keep his job, and then he leaves.

Her husband returns having noticed that Krogstad just left. He asks if Krogstad was asking Nora to help him keep his job, and Nora admits he was. Torvald is displeased that Nora would agree to help such a man. Krogstad is known for having forged signatures and evading punishment. Torvald ironically says to his wife that often criminals are known for having mothers who lied. The parents contaminate the children. He leaves the room, and Nora doesn't know what to think.