Charlie doesn't evince an objection when Feral makes his own outdoor sleeping arrangements and hangs around. Bella gets Feral to quiz her on Potions and lets him go through her Muggle book collection. And then he flaps away back to school and she waits out the rest of the summer and busses back.
The Deathly Hallows again - this time with a more comprehensive history, including biographies of the Peverell brothers.
"Not that I expect the information to be of much immediate practical use," he says. "Unless Feral has managed to get his hands on the Elder Wand. But I doubt it; rumour suggests it was destroyed."
"It doesn't have to be practical to be a good book," says Bella.
"Only if I can't find another good one by the time it is your birthday."
"I want to figure out how to destroy Dementors, if there is anything about that around. I haven't checked the school library yet."
"Of course if someone already knows how then I don't see why there would still be any, but maybe there have been options ruled out."
"Or it could take some incredibly nasty bit of Dark magic," Sherlock suggests.
Bella contemplates this, then decides, "It would have to be ridiculously nasty to not be worth getting rid of one of those. Especially the wild ones that can suck out souls whenever they feel like it. At least the domesticated kind only prey on a certain short list of people."
Sherlock shrugs. "Would you sacrifice a person to kill a Dementor?"
Bella thinks about this, and then says, "I bet I could find at least a few people I would trade in, particularly since Dementors kill people anyway just roaming around. I'd rather not. But people include, like, the people who decided to domesticate them and use them as prison guards. And people who are already dying of something."
"I bet it's possible to do it another way, though. We break the laws of physics all the time, and there aren't that many wizards compared to Muggles and so it wouldn't be that surprising if there was a way to do it that didn't hurt anybody that no one had run across yet."
"Well, up until I found out about magic I didn't think the laws of physics were breakable," explains Bella. "I don't see a strong reason to think there's only one layer of breakable but really convincing laws."
"What we really need is a physicist who understands magic," says Sherlock. "Until then it's all guesswork. It'll still be guesswork afterward, but less so."
The first day of classes, she goes to Transfiguration, seeing as it's first.
"Hi!" says Bella. The teacher isn't here yet. "So are you still taking Herbology in your elective slot?"