Something happened at precisely that moment. Both Claudia and Jamie tried to explain to me about it, but they couldn't quite. I know what happened, though I never told them. Having words and explanations for everything is too modern. I especially wouldn't tell Claudia. She has too many explanations already.
What happened was: they became a team, a family of two. There had been times before they ran away when they had acted like a team, but those were very different from feeling like a team. Becoming a team didn't mean the end of their arguments. But it did mean that the arguments became a part of the adventure, became discussions not threats. To an outsider the arguments would apppear to be the same beause feeling like part of a team is something that happens invisibly. You might call it caring. You could even call it love. And it is very rarely, indeed, that it happens to two people at the same time -- especially a brother and a sister who had always spent more time with activities than they had with each other.
From From The Mixed-Up Files of Mrs. Basil E. Frankweiler by E.L. Konigsburg, the only juvenile fiction I've ever read that contains a map of the Metropolitan Museum of Art.