....
Hm.
"I am okay with you occasionally showing up and poking me for my power to follow witches if you use my power to also aim for terrible people to eat," he says, because this is a very reasonable thing to ask of her, he thinks.
"Suits me fine! Where do you usually hang out? I'll lose your power as soon as I pick up another."
Slightly risky, kind of puts her in the same area his sister will be in, but he thinks Yvette will actually want to get help with her power anyway. And if she doesn't, he will tell Addy to meet him elsewhere for power pokes.
"England's lousy with vampires and my own witchcraft doesn't have the range to sweep the place, do you wander the whole thing?"
"All right. But just as well if you find me when you want to do more studying. Easier for you."
"At least until I get another decent tracking power!"
"Some of them. But tracking powers are easier to power up than some of the more esoteric things."
Addy has met many witch powers, and loves talking about them and the things she could get them to do!
But! Eventually Addy's human returns, and Blair would not like to freak the human out with The Second Strange Vampire; he bids Addy farewell and goes back to England.
He finds his sister. He tells her about the witch teacher who's kind of amoral but also really good at her job. ... Yvette is kind of uncomfortable with this but her power does not invade privacy and is highly fiddly. She could use a witch teacher.
She wraps up what things there are to wrap up in Oxford, and then Blair leads her back to Addy. ... And then persuades her to make the equivalent of ten thousand francs in twenty-four carat gold. Because it's funny.
Addy where are you, Blair has got a present. And a sister. He has both of those things!
Addy is in Estonia with a set of twins who do vocal mimicry and silent movement, respectively.
They're humans. They sleep. Addy is currently moving silently but that's no obstacle to Blair.
"Hi, Addy!" says Blair, lightly. "I got you a present."
He holds up his bag of gold triumphantly.
"What an appetizing present," Addy says, of Yvette, not the gold. Handshake?
"Oooooh. You've been working on this one, I can tell."
"A bit obsessively," she agrees. Her eyes are still newborn red. "It's really cool."
"Well, now I have an idea of where you got the gold."