"Dude, I've read Dracula, okay? I know that vampires kill people," Sam said.

He was starting to see why the others might not like Luke so much. From what Sam could see he seemed to jump to conclusions in a way that put people in a negative light. Or at least his tone seemed to suggest that. Maybe Sam was misreading the tone.

"I also know that draining blood from people is pretty nasty. Just because vampires are in doesn't mean I'm in their corner, rooting them on."