Buffy gets kidnapped and turned by The Master. Spike shows up and trains her for revenge.
Buffy pretends to be crazy at first and Spike can tell she's faking. He hates The Master, I think it has something to do with Dru.
It was a long WIP.

Brave New World by KaritaChan. Available at adultfanfiction dot net. WIP, 21 chapters. Not for the faint of heart.

Shelby133
http://spikeluver.com/SpuffyRealm/viewstory.php?sid=19153

Brave New World by JamesMFan Rated: 15 [Reviews - 493]

Summary: In "Get it Done" Buffy entered a portal to get information. Now, when she leaves it, she finds everything has changed; including her friends, her family and her world.

Disclaimer: The characters from Buffy the Vampire Slayer are owned by Joss Whedon, Mutant Enemy, and Fox studios. This story is not meant to infringe upon anyone's rights, only to entertain.
Categories: General Fics Characters: None
Genres: Romance, Action Warnings: Violence, Adult Language, Sexual Situations
Challenges: None
Series: None
Chapters: [59] Completed: [No] Word count: [104714]
Published: May 08 2006 Updated: September 14 2010

Guest
Couldn't find it at adult fan fiction

Here is the link for the story on aff.net

http://buffy.adultfanfiction.net/story.php?no=3329