The green eyes found the black, but after a second, something in the depths of the dark pair seemed to vanish, leaving them fixed, blank, and empty. The hand holding Harry thudded to the floor, and Snape moved no more.
He choose his road, but he kept looking back.
"Albus Severus," Harry said quietly, so that nobody but Ginny could hear, and she was tactful enough to pretend to be waving to Rose, who was now on the train, "you were named for two headmasters of Hogwarts. One of them was a Slytherin and he was probably the bravest man I ever knew."
"But just say..."
"...then Slytherin House will have gained an excellent student, won't it? It doesn't matter to us, Al. But if it matters to you, you'll be able to choose Gryffindor over Slytherin. The Sorting Hat takes your choice into account."
"Really?"
"It did for me," said Harry.
The letter was an incredible treasure, proof that Lily Potter had lived, really lived, that her warm hand had once moved across this parchment, tracing ink into these letters, these words, words about him, Harry, her son.
"We did it, we bashed them, wee Potter's the One, and Voldy's gone moudly, so now let's have fun!
"So young," he said finally, "to be fighting so many."