Trust No One (My Babysitter's A Vampire Fanfic)

Plot: Erica created an evil clone of herself. (By using Benny’s grandmother’s potions). She is trying to kill the Vampire Council. Sarah tries to fight Erica and she has a choice (to either kill Erica or get punished by the council.) The punishment is to leave the good side and join the evil vampires (knowing that Sarah’s biggest fear is becoming evil.) Ethan and Benny have a solution.
But will they tell Sarah in time?