Heroes on NBC

"Heroes" also had a pivotal episode Monday night in which much was explained. But can someone tell me whether the cheerleader's father is a bad guy or not? And what about the silent mind-scrubber guy who is always standing nearby? At least now I know that the blonde woman's ruthless alter ego is her dead pre-teen sister, killed by their father. I'm not sure how that makes her a "hero" but that's what we found out Monday. And Hiro was never meant to save the waitress. So why did Sylar kill her then? And why did Sylar go from a geeky and likable tall guy to a shadowy killer so quickly? It looks like he kills now to assume the heroes' powers for himself? Does he need to slice people's heads open? What does all this have to do with a bomb going off in New York? Wow, what a wacky story. Obviously the mystery is addictive.