Butterfly Effect ; H. Potter

75. occlumency.

Kreacher, it transpired, had been lurking in the attic. Sirius said he had found him up there, covered in dust, no doubt looking for more relics of the Black family to hide in his cupboard. Though Sirius seemed satisfied with this story, it made Harry uneasy. Kreacher seemed to be in a better mood on his reappearance, his bitter muttering had subsided somewhat and he submitted to orders more docilely than usual, though once or twice Harry caught the house-elf staring at him avidly, but always looking quickly away whenever he saw that Harry had noticed.

Harry did not mention his vague suspicions to Sirius, whose cheerfulness was evaporating fast now that Christmas was over. As the date of their departure back to Hogwarts drew nearer, he became more and more prone to what Mrs. Weasley called "fits of the sullens", in which he would become taciturn and grumpy, often withdrawing to Buckbeak's room for hours at a time. His gloom seeped through the house, oozing under doorways like some noxious gas, so that all of them became infected by it.

Harry didn't want to leave Sirius again with only Kreacher for company; in fact, for the first time in his life, he was not looking forward to returning to Hogwarts. Going back to school would mean placing himself once again under the tyranny of Dolores Umbridge, who had no doubt managed to force through another dozen decrees in their absence; there was no Quidditch to look forward to now that he had been banned; there was every likelihood that their burden of homework would increase as the exams drew even nearer; and Dumbledore remained as remote as ever. In fact, if it hadn't been for the DA, Harry thought he might have begged Sirius to let him leave Hogwarts and remain in Grimmauld Place.

Then, on the very last day of the holidays, something happened that made Harry positively dread his return to school.

"Harry, dear," said Mrs. Weasley, poking her head into his and Ron's bedroom, where the pair of them were playing wizard chess watched by Hermione, Antheia, and Crookshanks, "could you come down to the kitchen? Professor Snape would like a word with you."

Harry did not immediately register what she had said; one of his castles was engaged in a violent tussle with a pawn of Ron's and he was egging it on enthusiastically.

"Squash him – squash him, he's only a pawn, you idiot. Sorry, Mrs. Weasley, what did you say?"

"Professor Snape, dear. In the kitchen. He'd like a word."

Harry's mouth fell open in horror. He looked around at Antheia, Ron, and Hermione, all of whom were gaping back at him. Crookshanks, whom Hermione had been restraining with difficulty for the past quarter of an hour, leapt gleefully on to the board and set the pieces running for cover, squealing at the top of their voices.

"Snape?" said Harry blankly.

"Professor Snape, dear," said Mrs. Weasley reprovingly. "Now come on, quickly, he says he can't stay long."

"What's he want with you?" said Ron, looking unnerved as Mrs. Weasley withdrew from the room. "You haven't done anything, have you?"

"No!" said Harry indignantly, racking his brains to think what he could have done that would make Snape pursue him to Grimmauld Place. Had his last piece of homework perhaps earned a "T"?

"He couldn't have," said Antheia, picking up some of the chess pieces that had fallen over, "he's been here with us all break."

A minute or two later, Harry pushed open the kitchen door to find Sirius and Snape both seated at the long kitchen table, glaring in opposite directions. The silence between them was heavy with mutual dislike. A letter lay open on the table in front of Sirius.

"Er," said Harry, to announce his presence.

Snape looked around at him, his face framed between curtains of greasy black hair.