"...I hope you don't mean what I think you do."

"Is there, uh, a reason we're talking around it."

"Dunno! Is there anyone else in the library?"

"There is not, Miss Uzun.  I was being evasive for their sake."  He gestures at her friends, and rubs his forehead.  "To be absolutely clear - what exactly did you tell them?"

"Vampires, I have superpowers, demons, demon friend? Neither of them's going to the press or anything."

"When I asked if you were capable of discretion, I meant to impress upon you that you should not do precisely this."

"It's fine! And I need someone on the outside who knows like what I'm doing, I'm not gonna tell the parents I'm running out at night to fight vampires - but Kaylee and Tag can cover for me, can keep track of stuff like check ins and where I said I'd be, and raise the alarm if I don't check in."

"This is not a position a child should be put in!  And I recognize the irony of that statement, but it is not a position I would put you in if I had any other choice!  The Slayer is a target, which is why her identity is a closely guarded secret, and anyone who works alongside the Slayer is also a target.  I've spent my life preparing for that responsibility, and in your case - I would release you from it if I could.  But that life is not something your friends ever signed up for, and it is not a life they should be asked to live."

"Yeah we sorta did sign up for it actually."

"I did a lot of vague 'so do you want to know this infohazard' stuff first! And if I'm hanging with them they'll be targets, knowing my secret identity helps them stay safe!"

"Did you impress upon them that their lives would be in danger if they were careless with this information?  Did you explain to them that they would have to be more reticent with this secret than you yourself were, lest the people they tell let someone else know in turn, and so on until the information reaches a disguised vampire or an agent thereof?"

"Yes! I've dealt with big secrets before, I know how to read people as trustworthy!"

He sighs.  "I suppose the damage is done in any case."  To Tag and Kaylee: "I hope I don't need to tell either of you that you are not the Vampire Slayer and should not go hunting for vampires yourselves."

"I'm not an idiot, no.  Although for the record Nausicaa didn't mention anything with a definite article, she just said she had superpowers."

"The Slayer is a mystical title, passed on to a new, ah, teenage girl, every time the previous Slayer dies.  It is the source of your friend's supernatural abilities.  Slayers tend to find themselves entangled in significant events in the supernatural world."

"He honestly has yet to convince me it's any more impressive than a Captain America package. Which is still pretty fun, but I'm not exactly twisting reality into pretty shapes here."

"Often the Slayer will figure into prophecies, which can be as significant as any of her other abilities.  I must recommend in the strongest possible terms against any reality twisting."

"I'm not gonna, I'm just saying comic books lied to me."

"They will do that."

"...So, vampires?"

"Yes," Giles says. "I had planned to use this afternoon to continue Miss Uzun's Slayer training, but if you are to be informed, you should be fully informed."

He recapitulates his earlier crash course on vampires: invariably evil, drink blood, singed by holy water and crosses -

"Okay, now, hold on," says Tag. "Holy water is a real... you can just go to a Catholic church and... you know, pick up some holy water. It's not a secret magic thing that exists behind the masquerade. Are you saying Catholic priests have magic powers?"

"...I would not characterize it that way, no," Giles says. "But objects and substances can be imbued with - mystical significance - by methods far more pedestrian than their ritual use in one of the most widely practiced religions in the English-speaking world. Holy water is not magical itself, but magical things may react to it differently than they react to chemically identical water that has not been blessed, or water collected from dewdrops, or samples from particular significant bodies of water.  For example."

" - Okay so question, is the important thing the religious symbolism, or did those things become popular religious symbolism because vampires are inherently freaked out by the letter 't'?"

"The history of vampirism is somewhat unclear," says Giles.  "Vampires in particular don't seem to be repelled by other widely used religious symbols, certainly, so it can't be merely that they are susceptible to religious symbolism itself.  But demons and dark creatures corresponding to other cultures' mythologies tend to respond negatively to their own culture's rituals and symbols more often than to others', which is suggestive of religious symbolism being an important factor in imbuing an object or substance or symbol with mystical power.  Most experts agree that the, ah, anatomically modern vampire as it were, postdates Christianity by a number of centuries; I doubt that the cross was terribly harmful to anything vampire-like before it was a religious symbol."