The whole Mitchell going on a killing spree with Daisy, set to end Lucy was completely amazing. To just go there with a main character of the show, without any such excuses as souls or no souls, it was really scary in a good way.
I found the "rescue me from my evilness with love" - story very creepy to begin with, because like so many things about the being human vampires, it mirrors the behaviour of drug addicts, in this case how they can pull someone into coaddiction, always keeping up the premise that they can be rescued if the other person only loves them enough.
And then it falls, Lucy turns out to be traitor and suddenly no one is save.
Not that I could actually believe George wolfing out inside the school either.
*is awed and needs new episode*