Disclaimer: I own nothing. All Buffy the Vampire Slayer characters and Alexandre Dumas characters are the property of their original owners.
"Ah, yes, that gown is special," said a voice with a British accent from behind the two girls, startling Buffy and Willow, who turned around to see a mature man giving them both an oily smile. The proprietor of the Halloween costume shop continued, "It's in an eighteenth-century style, but the material itself is from a much older gown worn by a French noblewoman, more than a century earlier, I think."
"I'll take it!" beamed Buffy.
"Certainly," murmured Ethan Rayne, who stepped forward to bring the gown over to the register counter, smirking to himself at the extreme trouble the Slayer would be in after Janus was invoked later that night.
Even though the profession of an actress was regarded with disdain in her time, with any woman performing on the stage being considered no better than a prostitute, the personality who had come to life after the casting of the chaos magic was more than competent at presenting to the world whatever behavior, mood, and appearance that was necessary. After all, she'd once seduced the servant guarding her by pretending to be a penitent, pious woman who truly loved her captor, and in the end she had coldly sent him off to assassinate his noble lord.
So, all during that night, she had feigned being a shrieking, hysterical girl, while in fact she'd been eagerly studying and analyzing everything of the new and strange world she'd somehow appeared in. Further, she became determined that no matter what, she was not going to vanish into non-existence again.
In the end, she managed, by sheer force of will, to keep a part of her personality in the mind of Buffy Summers when that Halloween was over. As she waited and watched, all while making her plans, she allowed herself some moments of amusement by having the girl whose mind she was sheltering in become perfectly fluent in French.
*Ah, Richelieu, my master, you would be most proud of me,* thought Milady de Winter.
Author's Note: Yes, that really is the first name of the villainess appearing in the Dumas novel "The Three Musketeers," though it's sometimes translated into English as Clarisse or Clarice.
Further Note: Had a message from JoeHundredaire: *Please put a note in the existing story that you're accepting/seeking co-authors; any extension by another author would be done in that fashion, not a separate story as an answer to a challenge.* Okay, no challenges; but since I never intended to do anything more than this story; instead, if any other author wants to use this idea to write more about what might happen next (in any and all possible situations), they can freely do so. Just post a note in your story saying where you got this from.