The Salvatore brothers ask for backup from a surprising source when Elena calls their bluff. Katherine is suspicious when Bonnie makes her an offer.

Someone has been attacking patients at the hospital. A violent wind storm causes a power outage and ghosts suddenly appear - some with good intentions and some bent on revenge.

Season finale: It's Graduation Day. Damon's life is in danger and Elena faces an epic confrontation. Plus, Stefan discovers a horrifying clue to the mystery surrounding Silas.