"Is my new librarian a Watcher?" she asks Sherlock the day after Mr. Giles joins the faculty.
"Slightly more troublesome. I know of only one method, and apart from its many other problems it only prevents you from dying of some things. True immortality is beyond my means."
"Yeah, and it has that inconvenient personality revision problem. I want me to live forever, I don't want some superficially similar creature to live forever."
"I consider myself to have continuity with the person I was, but I know not all vampires do. The objection is fair."
"What exactly do souls... do? I mean, I know what usually happens when the soul is removed. But it's apparently not consistent, I don't know the psychological mechanisms involved, and I'm wondering what function precisely they tend to serve."
"Interesting question," he says. "I could tell you what mine did for me, I suppose. Or try to. I've never exactly thought of it in those terms."
"...When I had a soul," he says, "I cared about abstract ethical concerns like when precisely murder is wrong and whether or not I counted as a real person. They meant something to me in an immediate way. There were emotional consequences to violence that now do not exist. My repertoire of available actions is expanded; I can choose to steal or eat people or torture someone to death with no consequences except the practical."
(She does not sound impressed.)
"Yeah, that makes less sense than half the things they tell me in my Government class, and let me assure you, many things they tell me in Government are nonsensical."
"What's the... shift in ethical feeling... like? I have a rudimentary understanding of what it might be like to be that way, but less of what it would be like to become so - to wake up and find one's brain rearranged."
"I hardly noticed at first," he says. "I was ocupied by other concerns. It did occur to me while waiting for Obadiah that while I would have thought about torturing him to death before the change, I probably would have left out the torture in the end."
"I reiterate that he had my entire family murdered. Yes, I would have killed him. I'm fairly sure he assassinated Tony's parents, for that matter."
"Oh, yes, I understand completely. Under the circumstances I can barely manage to blame you for the torture, let alone the killing. Just wanted to confirm. Tony's parents? They'd be genetically yours too, whether or not you ever met them. I confess I am quite ignorant about how clones slot into their creator's families."
"Poorly," he says. "Tony's parents were not particularly close to him, but at least they had met."
"You would've had to pretend to be twins with Tony regardless - was he like your brother, or what?" Her next guess is 'parent'.
"Not remotely," he says. "Nor my father, before you ask. He was... Tony. I loved him. Further labeling did not seem productive."
"Do Watchers tend to know much about magic?" Bella asks in a complete topic change. "I'm still not accomplishing anything with what supposedly simple spells I've attempted and unless Slayers just fundamentally can't do magic, I'm missing something obvious that someone who knows magic would be able to tell me. It might be worth exposing myself to lots of crustiness just to get that figured out. Of course, maybe there are less crusty freelance witches who can take students and wouldn't need to know I'm the Slayer to find me worth their time."
"...I have no concrete data to support this," he says, "but my feeling is that the Watcher's Council is not an organization you want in your life. Even if they can teach you about magic, and I don't know if they can, or would."