Read the excerpt from act 2 of A Doll's House.
Helmer: Rank led me to expect a splendid transformation.
Rank: [in the doorway] I understood so, but evidently I was mistaken.
Nora: Yes, nobody is to have the chance of admiring me in my dress until tomorrow.
Helmer: But, my dear Nora, you look so worn out. Have you been practising too much?
Nora: No, I have not practised at all.
Helmer: But you will need to—
Nora: Yes, indeed I shall, Torvald. But I can't get on a bit without you to help me; I have absolutely forgotten the whole thing.
Helmer: Oh, we will soon work it up again.
Nora: Yes, help me, Torvald. Promise that you will! I am so nervous about it—all the people—. You must give yourself up to me entirely this evening. Not the tiniest bit of business—you mustn't even take a pen in your hand. Will you promise, Torvald dear?
Helmer: I promise. This evening I will be wholly and absolutely at your service, you helpless little mortal. Ah, by the way, first of all I will just— [Goes towards the hall door.]
Nora: What are you going to do there?
Helmer: Only see if any letters have come.
Nora: No, no! don't do that, Torvald!
Helmer: Why not?
Nora: Torvald, please don't. There is nothing there.
How does Ibsen use dramatic irony to create suspense in this passage?