The next day he passed Alai in the corridor, and they greeted each other, touched hands, talked, but they both knew that there was a wall now. It might be breached, that wall, sometime in the future, but for now the only real conversation between them was the roots that had already grown low and deep, under the wall, where they could not be broken.
"I may have used Valentine," said Graff, "and you may hate me for it, Ender, but keep this in mind — it only works because what's between you, that's real, that's what matters. Billions of those connections between human beings. That's what you're fighting to keep alive."