Elena puts herself in a dangerous position as she searches for the truth about Katherine's past and what her own future may hold. Knowing that Stefan would never agree to her plan, Elena swears Caroline to secrecy. Damon uses a new-found confidant to help him try to discover the real purpose and power of the moonstone. Jeremy and Bonnie meet Luka, a new student with a surprising family history.

As the full moon approaches, Caroline helps Tyler prepare for the transformation he is powerless to stop. While Stefan and Katherine play mind games on one another, Damon and Alaric are suspicious when a stranger named Jules shows up in Mystic Falls, searching for her missing friend, Mason. Elena is frustrated at the lengths Jeremy and her friends have gone to in order to keep her safe. Bonnie and Luca work together on a spell, while still keeping secrets from one another. Finally, Elijah makes an unexpected appearance with an offer that could change everything.