Thanks so much! :)
I'm searching for a fic with the barest of information about it. I think Spike is unchipped and unsouled, but I'm not sure about that. He captures Xander, and Xander knows the postures and attitudes to display because he figured he'd get caught sometime, and wanted the best chance to survive. So he studied some books Giles had.
And that's all I can remember. Sigh. I'm hopeless, sometimes.