Parts 1 and 2 are here
Giles turned his gaze on Spike. “I suppose I should thank you for helping Buffy remain alive,” he said. “Although I’m extremely curious as to why you did it. What is your motivation for such unusual behavior?”
Buffy had turned to face Giles, leaving her back to Spike who once again rested one hand lightly against it.
“When I figure that out, I’ll let you know,” Spike said, eyes briefly flaring yellow. “Maybe. Maybe I’ll just decide it’s none of your business.”