Heroes

I think I must have missed some episodes of Heroes. What happened to the little girl Matt and Mohinder adopted or whatever? And what happened to Nikki/Jessica? Not that I cared about her character, but I liked the kid. What happened to him? I like what's going on on the show right now, I'm just trying to figure out how they got to this point. Oh, and why doesn't Peter just go grab Nate and fly him up into the air and drop him? That way either everyone would see that Nate is an evil mutant, or Nate would go splat! Either outcome would make me pretty happy right now, because he's just pissing me off.