"...I dislike the sound of invasive scrying, more details on invasive scrying?"

"Okay, scrying overview... someone who has enough things to identify you with can use a scrying spell to look at what you're doing right then, or where you were in the past, or find out other information about you. Useful scrying is kind of an esoteric discipline, but someone who's really good at it could use your name and a picture of you to watch any particular few minutes of your life they felt like specifying. There are not a lot of people who are that good at it. And it's harder when, for example, your name is not that specific to you because it's one syllable that's a reasonably common nickname. It's also possible to scry specific locations instead of specific people, but that way is more fragile - it can be disrupted pretty easily if the location you're trying to look at is even a tiny bit warded, or if there's any other strong magical influences getting in the way."

"Would this be improved if I went by a nickname that is not related to my real name? How does any of this do with stuff like seeing in the dark? What constitutes 'other information'? What information do they need to specify a span of minutes or a location?"

"It could be somewhat improved. I do something like that," she says. "But if you changed to something you identify with more strongly, or that was more unique, it could just make things worse. Scrying can compensate for poor lighting conditions pretty handily, if it's a good scry. I've heard of someone who was particularly good at that kind of magic being able to find out someone's name using a photo and a glove they'd lost. Actually, now that I'm on the subject, sympathetic magic safety 101: Don't let anyone you don't trust get their hands on your blood, hair, fingernail clippings, or other miscellaneous detached body parts. Clothing that comes in pairs, like gloves or socks, if you lose one then ditch the other - burn it, if you're feeling really paranoid that day. Don't lose any objects you're strongly sentimentally attached to. Most people go through their lives just fine without paying attention to any of that except maybe the hair and fingernails, but if you're going to be making enemies who can do magic, those are the things that could make it easier for them to do magic to you."

"James isn't your real name?" he asks. He takes notes on the rest of it. "I'm going to need a little incinerator, I guess, I have bad demonic habits and keep making stuff almost as though I still had access to my tiny black hole."

"James is quite possibly more real to me than the name on my birth certificate, but fewer people know it. So people trying to scry me based on the other name won't get very far, because the personal connection is more important than what somebody wrote down when you were born."

"Okay."

"Anyway, your other question about scrying - the kind of information you need to specify something is a pretty squishy category. In general it corresponds roughly to the kind of information you'd need to specify it in conversation - 'So-and-so's fifth birthday', 'Sunnydale Main Street in front of the library', that kind of thing."

"How about 'most private moment' or something like that?"

"Hmm... it's harder to specify things that way. When somebody's first birthday was is pretty much a fact, but when their most private moment was is a judgment, and probably not one that a lot of people have made, and the people who have might not agree with each other. The guideline that springs to mind is, if you had video footage of your whole life and you handed the pile over to someone who had no idea who you are and a lot of time on their hands, could they find what you're looking for based on that specification? So, 'fifth birthday' would be pretty easy, 'first kiss' would take some looking but probably not a lot of trouble, 'most private moment' would mean they'd have to go through carefully and think about it and might not be able to decide even then."

"Okay. In your opinion would this work even though the overwhelming majority of my life has been conducted in an alternate universe?"

"I have no idea, but wouldn't be inclined to rule it out without seeing someone try it and fail."

"Do you suppose I could direct your aunt to something relatively innocuous to find out?"

"Yeah, sure. My aunt can be bribed to do you magical favours pretty much indefinitely as long as you can keep coming up with cool chess sets and she doesn't run out of room to store them."

"Handy."

"Yep."