I can't let them know

(This starts off in 4x21 of The Vampire Diaries and then it moves to The Originals)

Elena now a vampire has her humanity off and Damon and Stefan have been trying to get the cure for her but she doesn't want it. She threatens to go on a killing spree if they don't stop , so they try to get her to turn her humanity on herself. When she goes to prom with Rebekah to insure Rebekah gets the cure, Stefan and Damon finds it's the perfect opportunity to start to mix up her feelings. After Rebekah lost prom queen to Bonnie, Elena decides to go after her. While trying to kill her Bonnie starts to use her powers on Elena. While Elena is unconscious Stefan and Damon thinks its time for plan B. While plan be work?