Keep watching the Buffy reruns, Bruce, to get the full back-story. I'd summarize for you here, but there's simply too much material to cover in one post. You've got the general idea; Spike's early episodes were pretty scary. He's certainly, um, evolved. Angel did get evil again, then good again, and left mainly because he saw no future for himself and Buffy. But it's more complex than that. Keep watching. If you can, try and rent the season sets and just wacth them through. they're well worth seeing.