After three days of fasting, Esther puts on her prettiest frock and heads in to see the king. He holds out the sceptre to her, granting her permission to speak. He offers her anything she wants, because she's so freaking hot, even half the kingdom. No, she just wants him and Haman to come to a banquet. He agrees immediately.
At the banquet, the king knows something is still up so he asks her to come out with it. She waffles a bit, and only asks them to come back again tomorrow for another meal.
Haman leaves, in a great mood because he got to schmooze with the king and queen, but it sours immediately when he comes to the palace gate and meets Mordecai, who has clearly learned nothing, and refuses to bow again. He goes home to his wife and raves about the banquet and Mordecai's foolish pride, and vows to build a 50-foot gallows the next day to hang him from. Well deserved, I'd say.