"Is my new librarian a Watcher?" she asks Sherlock the day after Mr. Giles joins the faculty.
"Well, you seemed to be able to understand the format I wrote my notes in. You could just tell me."
"Maybe not, but worth a shot," she says, disengaging and plucking the notebook from the floor to hand it over. She also has a pen in her messenger bag. (And a pencil, but that seems like it might be a vaguely threatening thing to offer a vampire.)
He spends a minute or so staring thoughtfully at the page, and then writes a proposed subroutine and hands her back the notebook.
"Yeaaaah I could install that but I think it's ugly and do not want it in my brain," she says, tossing the notebook back where she got it. "Maybe if I ever need to leap into an uncomfortable form of expertise overnight for an emergency we can try that. Okay, there's got to be some other way for me to figure out what goes in, hm." She begins to pace.
"Can you be - repetitive? Can I try a dozen things against the same attack pattern - a serious one, not one you're dumbing down for me, although please don't take my arm off or anything - and then see what works best, what feels right, and then figure out a higher level of abstraction that would've generated that without knowing what was coming?"
"Excellent. Sequence of about thirty seconds to start, we can step it up as I get better at this and have more complicated basics to build on. Autopilot engaged, hit me," she says, dropping into stance.
When the thirty seconds are up and she's sprawled on the floor, she thinks. If she'd seen that coming and countered thusly -
Autopilot off, up on her feet, and - "Again."
Again. Precisely the same, to start, although when she deviates from the original script he adjusts to match.
"Again."
She picks up her notebook, scribbles out what she was doing, and seeks a pattern.
This takes her about ten minutes of writing, drawing arrows, referring back to earlier notes, and tapping her pen on the page. Sherlock is welcome to read over her shoulder.
When she's done, she writes the abstracted adjustment with all the triumph of a math professor chalking a theorem onto a blackboard. She closes her eyes, thinks it into place - it's so much easier to work with the Slayer stuff than it is to handle anything else, it's like she's got root access, like the instinct package has handed her a scalpel and begged for surgery - and gets up.
"Surprise me," she says, grinning.
He's still better. But she's approaching him.
Half a dozen thirty-second-sequences worked through, abstracted, and turned into heuristics for installation later, she is able to fight him to a standstill on the first try at a new one.
It's not perfect - she catches one blow across her shoulder and has to do something inelegant to get away from a kick - but they wind up with her sitting on his back and both his arms pinned in place.
She comes up with solutions to the rough patches, repeats the sequence, and winds up in a different but still victorious position on the second try. She makes and installs another high-level revision. "I feel like I'm doing computer programming on my brain," she says. "I mean, I've always described it kind of like that, saying 'hack' and stuff, but this is a whole 'nother thing. Call it a night? Shoulder's being annoying."
And home she goes. "Thanks," she says when they get close enough that if she steps any nearer the house the porch light will come on. "You're really helpful - I would not be at all pleased about having to work on this with live ammunition, so to speak."
She likes him, she wouldn't want him cooked.
At dusk she goes outside with Sherlock's jar of blood and the usual clothespin on her nose.