PG. This part is just BtVS, but this sequence, dealing with the vampire in the basement of the brothel and his story, will eventually be an RPF crossover, possibly with other fandoms coming into play from time to time.
They were keeping him in a cage when Big Daddy G first found Betty, first brought her there. Kept him because he woulda been about a foot taller, fifty, sixty pounds heavier and a hell of a lot stronger than Betty even if they'd both been human. With him a vamp and her a shiny new Slayer, well, Willow had read the cards and Miss Jenny across the way had seen it too, there'd been a Slayer coming, and Giles had wanted a way for her to practice.
They'd had him in a cage for a few weeks before she finally broke, before she buried Mama and ran the hell out of LA, and now that you mention it, out of the Republic of California punto, to get away from the bill collectors, ran to Infierno 'cuz she'd been having weird dreams and there'd been vamps chasing her and it seemed like a place that might have answers, and because maybe no one would follow her there, and went knocking at the door of the nicest-looking brothel that would take a dumb Dora like her.
Willow had already balled around and come up with a collar. Like the ones some of the people outside of the city had for their dogs, and she'd rigged up an invisible fence around the basement, too. They had stun guns, so Betty asked Giles why they hadn't just used them; knocked him out and put the collar on and let him out of the cage.
He'd said "Because we've been waiting for you," and then explained that they weren't hiring, but he would make an exception for her, and after he explained, she knew it wasn't 'cuz she had nice bubs.
Which she didn't, by the way, but no one really cared about that when they hired her, 'cuz they wouldn't scare the horses, either.
If you had horses.
No one did, but theoretically speaking.
"Because we've been waiting for you," Giles had said, and handed her the collar, the keys to the cage, and opened the door to the basement.