“You’d better be in Slytherin,”

“You’d better be in Slytherin,” said Snape, encouraged that she had brightened a little.

“Slytherin?”

One of the boys sharing the compartment, who had shown no interest at all in Lily or Snape until that point, looked around at the word, and Harry, whose attention had been focused entirely on the two beside the window, saw his father: slight, black-haired like Snape, but with that indefinable air of having been well-cared-for, even adored, that Snape so conspicuously lacked.

“Who wants to be in Slytherin? I think I’d leave, wouldn’t you?” James asked the boy lounging on the seats opposite him, and with a jolt, Harry realized that it was Sirius. Sirius did not smile.

“My whole family have been in Slytherin,” he said.

“Blimey,” said James, “and I thought you seemed all right!”

Sirius grinned.

“Maybe I’ll break the tradition. Where are you heading, if you’ve got the choice?”

James lifted an invisible sword.

“‘Gryffindor, where dwell the brave at heart!’ Like my dad.”

Snape made a small, disparaging noise. James turned on him.

“Got a problem with that?”

“No,” said Snape, though his slight sneer said otherwise. “If you’d rather be brawny than brainy – ”

“Where’re you hoping to go, seeing as you’re neither?“ interjected Sirius.

James roared with laughter. Lily sat up, rather flushed, and looked from James to Sirius in dislike.

“Come on, Severus, let’s find another compartment.”

“Oooooo…”

James and Sirius imitated her lofty voice; James tried to trip Snape as he passed.

“See ya, Snivellus!” a voice called, as the compartment door slammed…

And the scene dissolved once more…

Harry was standing right behind Snape as they faced the candlelit House tables, lined with rapt faces. Then Professor McGonagall said, “Evans, Lily!”

He watched his mother walk forward on trembling legs and sit down upon the rickety stool. Professor McGonagall dropped the Sorting Hat onto her head, and barely a second after it had touched the dark red hair, the hat cried, “Gryffindor!”

Harry heard Snape let out a tiny groan. Lily took off the hat, handed it back to Professor McGonagall, then hurried toward the cheering Gryffindors, but as she went she glanced back at Snape, and there was a sad little smile on her face. Harry saw Sirius move up the bench to make room for her. She took one look at him, seemed to recognize him from the train, folded her arms, and firmly turned her back on him.

The roll call continued. Harry watched Lupin, Pettigrew, and his father join Lily and Sirius at the Gryffindor table. At last, when only a dozen students remained to be sorted, Professor McGonagall called Snape.

Harry walked with him to the stool, watched him place the hat upon his head. “Slytherin!” cried the Sorting Hat.

And Severus Snape moved off to the other side of the Hall, away from Lily, to where the Slytherins were cheering him, to where Lucius Malfoy, a prefect badge gleaming upon his chest, patted Snape on the back as he sat down beside him…

And the scene changed…

Lily and Snape were walking across the castle courtyard, evidently arguing. Harry hurried to catch up with them, to listen in. As he reached them, he realized how much taller they both were. A few years seemed to have passed since their Sorting.

“…thought we were supposed to be friends?” Snape was saying, “Best friends?”

“We are, Sev, but I don’t like some of the people you’re hanging round with! I’m sorry, but I detest Avery and Mulciber! Mulciber! What do you see in him, Sev, he’s creepy! D’you know what he tried to do to Mary Macdonald the other day?“

Lily had reached a pillar and leaned against it, looking up into the thin, sallow face.

“That was nothing,” said Snape. “It was a laugh, that’s all – ”

“It was Dark Magic, and if you think that’s funny – ”

“What about the stuff Potter and his mates get up to?” demanded Snape. His color rose again as he said it, unable, it seemed, to hold in his resentment.

“What’s Potter got to do with anything?” said Lily.