What happens next?

Willow summons another demon

Again Willow went through the ritual chant and again a figure appeared out of thin air in the center of the pentagram. A dark-haired figure in a black dress whose face looked like that of --

"Amy?" asked Buffy. "Amy Madison? Since when did you become a vengeance demon?"

"Since when did you not become a vengeance demon?" said Amy Madison. "Oh, wait. That was a different timeline. Which one am I on now? The one where the Master wins and -- oh, no. Your neck's still intact."

"What does that mean?" asked Buffy.

"Oh, don't worry about it," said Willow. "She's just pulling your leg. So how long have you been a vengeance demon, Amy?"

"Actually, I'm not a vengeance demon," said Amy.

"Oh, good," said Willow.

"I'm a vengeance angel," said Amy.

"What's the difference?" asked Willow.

"I'd tell you but I already explained it to you on another timeline and anyway, you'll find out soon enough," said Amy.

"Well, anyway, I need you to do me a favor," said Willow. "You see my friend Buffy here --"

"Hey, Buffy!" cried Amy. "You're still naked after all this time?"

"What do you mean, 'still naked'?" asked Buffy.

But Amy did not answer the question.

Instead she said, "Sorry, Willow. No can do. I gotta run."