“But that’s a really serious thing to say

“But that’s a really serious thing to say!” said Hermione. “Are you – are you talking about your sister?”

Aberforth glared at her: His lips moved as if he were chewing the words he was holding back. Then he burst into speech.

“When my sister was six years old, she was attacked, by three Muggle boys. They’d seen her doing magic, spying through the back garden hedge: She was a kid, she couldn’t control it, no witch or wizard can at that age. What they saw, scared them, I expect. They forced their way through the hedge, and when she couldn’t show them the trick, they got a bit carried away trying to stop the little freak doing it.”

Hermione’s eyes were huge in the firelight; Ron looked slightly sick. Aberforth stood up, tall as Albus, and suddenly terrible in his anger and the intensity of his pain.

“It destroyed her, what they did: She was never right again. She wouldn’t use magic, but she couldn’t get rid of it; it turned inward and drove her mad, it exploded out of her when she couldn’t control it, and at times she was strange and dangerous. But mostly she was sweet and scared and harmless.”

“And my father went after the bastards that did it,” said Aberforth, “and attacked them. And they locked him up in Azkaban for it. He never said why he’d done it, because the Ministry had known what Ariana had become, she’d have been locked up in St. Mungo’s for good. They’d have seen her as a serious threat to the International Statute of Secrecy, unbalanced like she was, with magic exploding out of her at moments when she couldn’t keep it in any longer.”

“We had to keep her safe and quiet. We moved house, put it about she was ill, and my mother looked after her, and tried to keep her calm and happy.”

“I was her favourite,” he said, and as he said it, a grubby schoolboy seemed to look out through Aberforth’s wrinkles and wrangled beard. “Not Albus, he was always up in his bedroom when he was home, reading his books and counting his prizes, keeping up with his correspondence with the most notable magical names of the day,”

Aberforth succored. “He didn’t want to be bothered with her. She liked me best. I could get her to eat when she wouldn’t do it for my mother, I could calm her down, when she was in one of her rages, and when she was quiet, she used to help me feed the goats.”

“Then, when she was fourteen… See, I wasn’t there.” said Aberforth. “If I’d been there, I could have calmed her down. She had one of her rages, and my mother wasn’t as young as she was, and… it was an accident. Ariana couldn’t control it. But my mother was killed.”

Harry felt a horrible mixture of pity and repulsion; he did not want to hear any more, but Aberforth kept talking, and Harry wondered how long it had been since he had spoken about this; whether, in fact, he had ever spoken about it.

“So that put paid to Albus’s trip round the world with little Doge. The pair of ‘em came home for my mother’s funeral and then Doge went off on his own, and Albus settled down as head of the family. Ha!”

Aberforth spat into the fire.

“I’d have looked after her, I told him so, I didn’t care about school, I’d have stayed home and done it.

He told me I had to finish my education and he’d take over from my mother. Bit of a comedown for Mr. Brilliant, there’s no prizes for looking after your half-mad sister, stopping her blowing up the house every other day. But he did all right for a few weeks… till he came.“

And now a positively dangerous look crept over Aberforth’s face.