Bella is careful to go to the magic shop during lunch - not at night, not when her parents might notice her leaving home, not when her teachers might notice her skipping classes. She is careful to wear her crucifix, carry her holy water gun, keep her demon whistle ready to hand. She is careful to wrap her occult purchases in disguising packaging: chip bags, gym clothes, grocery totes. She is careful to restrict herself to spells that are necessary - whether "necessary" means for the result or for managing her mercifully limited dependence on the damn things is always carefully recorded in opaque code in her notebook, and if the ratio gets too low, she goes cold turkey outside dire emergencies for at least three days. This is uncomfortable, and it kills her class performance and her temper for those days, but she has to be careful. Her parents don't want her doing magic. They're afraid she'll get addicted. (Done.) They're afraid she'll get snapped up by the USADI, drafted into casting more than she can handle or things that shouldn't be cast at all. (Not done; and another reason to be careful.) They're afraid she'll get a spell wrong and hurt herself. (Not done; yet another reason to be... careful.)
She is confident that witchery has saved her life at least twice, possibly as many as four times; she's sure it's saved others more than that. A month ago she located the hiding place of the Gem of Amara, determined it ludicrously easy to find, and conjured it to her for safekeeping in Forks under considerably more sophisticated wards placed gradually over the course of weeks. (Not in the house; any vampire with a non-vampire demon friend could bypass that protection and she doesn't want to put her parents in harm's way. But in a house, because the protection is non-negligible; USADI experimental reports say that squatters count as living human residents, and she can get into the basement section of a consistently occupied old Victorian close to the city walls without bothering - or alerting - those who make it their hangout.) With this gem more securely stowed, it will at least take longer for some vampire or other to come across it, render themselves invincible, and slaughter an entire metropolitan area before USADI calls in something sufficiently heavy-duty to get around the damn thing.
She's looking into how to destroy it, but while Forks has the advantage of safety, it also has the disadvantage of a relatively cruddy magic shop. The Witchnook is capable of special-ordering things, albeit with a lag time of weeks or months, but Bella's not sure how far to trust the proprietor. She supposes her parents don't know she's a witch yet, so it can't be "not at all", but, well. She'll come up with some other books to order in the same batch, as cover.
Bella is careful when she goes out at night. She wears her cross, she carries her holy water gun and her demon whistle. She sets her alarm clock at maximum volume for fifteen minutes after she expects to be back, with a note taped to it for her parents, in case she runs into trouble. And usually she doesn't go out at night at all.
Tonight she needs a spell ingredient that cannot be out of doors during the daylight without losing its potency, though, so if she wants to get it home at all, she is going to have to spend ten minutes walking to the Witchnook, pay for her twilight powder, and spend ten minutes walking back.
Forks has walls.
She'll be okay.
She'll be careful.
She puts them all in her bag.
And she looks at the Gem in her hand.
She does not know any spells to sabotage the fucking thing.
"What are you going to do?" she asks softly.
"The same thing I've been doing all this time, but in daylight," he says. "You probably imagine I'm going to kill lots of tasty humans, but it isn't true. I was bored of murder within a week of turning and I haven't done it since."
"So if I just sit here," she says, "are you going to torch the building to chase me out?"
"I don't know," he says dryly. "Would you like to try it and see? It seems to me that in that situation each outcome is the opposite of how you'd like it: a murderous vampire will set the building on fire and get the ring, and a nice friendly one will wait patiently for a few hours and then go away and leave you to the mercy of the next fellow."
"You explain how you found me by way of asserting that the name is not a gimmick, and then you seem so sure that some other vampire, not named Sherlock Holmes, would inevitably also find me," Bella observes.
"Being Sherlock Holmes is how I found you first. I don't claim that I am the only vampire on this entire planet smart enough to make the same connections. Although I might be. Regardless, the other vampire is mostly rhetorical; the point is still that by staying inside you are arranging things so that I will get the Gem of Amara if and only if I shouldn't."
With the battery out of her phone she can't check the time on it, and she doesn't want to ask him if he has the time. But she thinks she could make it home before the alarm if she concludes here quickly.
"On the premise that I'm going to get out of this alive," she says suddenly, "do you want to offer any incentives for me not to report your description, last known location, and gem possession to the USADI as soon as I can?"
"I can't think of any," he admits. "I suspect you will not be swayed by the fact that I would find it slightly inconvenient if you did, and you have no reason to believe that I will not be using it to kill anyone."
"And I don't have any way to check up on you, not unless you take up permanent residence here and we continue not to have vampire-related deaths," she mutters.
"Should I not be? I don't have a better destination in mind," he says. "There's a certain appeal to the nomadic unlife, but mostly what I'm looking for is something interesting enough to keep me away from sunrises. You're reasonably interesting. And the deer in these parts are very tasty."
"Your sunrise-related behavior will be irrelevant with this thing." She holds up the ring. And with her other hand she pinches the bridge of her nose. "So I give you this, you leave, I take my batteries and go home, and I keep my mouth shut as long as I see you around too routinely for you to be nipping off to Port Angeles for snacks and Forks goes on with its lovely safety record. Yes?"
She tosses him the ring.
"Scram, I need to be home inside of ten minutes if I don't miss my guess."
She resets the alarm with a minute and a half to spare.
She updates her in the event of my death file on her laptop.
She will have to go get her twilight powder some other night.
It's for destroying the Gem of Amara, and she sees no strong reason she won't be able to perform the final act of will that constitutes the spell while the ring's on a vampire.
She'll quietly go about getting her materials and then if he doesn't behave she'll have her ace in the hole.
She goes to sleep.
The next day, the school is abuzz: there is a new student. His name is John Escott and he was orphaned by vampires; he believes one or both of his parents might have turned, and he wants to live somewhere safe and out of the way where they won't think to look for him and couldn't get in if they did.
Okay then.
This will pretty thoroughly qualify him as Probably Not Running To Port Angeles For Snacks.
She makes as though she doesn't recognize him, when he turns up in her bio class.
He tolerates being the focus of everyone's attention reasonably well, although it is clearly wearing on him. Yes, he is from England. London specifically. Yes, his parents were murdered by vampires, thank you for fucking well reminding him, he had almost forgotten, don't you have a class to pretend to pay attention to?
"Hi," she says. "I'm Bella."
He will not have to fake reacting as though her name is novel. He never asked for it.
"I have heard that." Well, she has. She passes him yesterday's class notes, meticulous and interspersed with bits of Angela's handwriting; this notebook is school stuff exclusively. "My lab partner is sick today, but she'll be back."