Chapter 22 of Rules by Cynthia Lord is entitled “A real conversation takes two people.” This “rule” serves to sum up what Catherine has learned about friendship throughout the novel. Catherine is at the dance, waiting for Jason to arrive, and she is worried that he won't show up because of the disagreement they had at his birthday party.
When Jason comes, Catherine can tell that he is still upset with her, but she tells him that she really needs to talk to him. Catherine tells Jason the whole truth, about how weak she has been and how much she is hurt when other people stare at her brother and how she didn't tell Kristi everything about Jason. Catherine admits that she was “scared what she [Kristi] might think of me, not you.”
As Catherine and Jason are talking, Kristi and Ryan arrive, and Catherine introduces them to Jason. Kristi is upset that Catherine hasn't told her that Jason is in a wheelchair or has to speak by pointing to cards. Catherine apologizes and admits that she should have told Kristi the truth. Kristi doesn't really accept her apology and walks away with a mere “See you around.” This is one friendship that likely won't survive and never has been especially deep or meaningful to start with.
However, the friendship between Catherine and Jason does survive. Catherine has more to show Jason, but he says he doesn't need the last card. He wants to to dance, and he wants Catherine to dance with him. She agrees and follows Jason out onto the dance floor. She lets go of her fear and begins to dance, putting Jason before herself and making their friendship more important than her rules.