What happened then: they became a team, a family of two. There had been times before they ran away when 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 appear to be the same because 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 the mixed up files of Mrs. BasiL E. Frankweiler, p. 39