21. She's Come Undone

Complete story — includes the ending

Damon and Stefan try a brutal new approach to provoke Elena into turning her humanity back on, and Caroline is frustrated when her attempt to intervene backfires and Elena attempts to kill her. When Elena figures out a way to call the Salvatore brothers' bluff, they call on Katherine to create real fear. Katherine has a go, pushing her hand into Elena and grabbing her heart. Then she deliberately leaves the door unlocked so that Elena can escape. Matt gives Rebekah some unsolicited advice on her life choices, and she tries to help him in return. Caroline has a confusing and dangerous encounter with Klaus, who turns out to be Silas looking for Bonnie. Silas is persistent, and mortally injures Caroline's mother to take her place. Bonnie reaffirms her promise to help Silas open the veil to purgatory, and Caroline has to inject some of her blood into her mother to bring her back to life. Katherine is suspicious when Bonnie makes her the offer of Silas's immortality and invulnerability in exchange for the tombstone that Katherine took from the island, which Bonnie needs to lift the veil between our world and purgatory. Katherine appears to accept the deal. Meanwhile, the Salvatore brothers use Matt to switch on Elena's humanity, with Damon snapping Matt's neck in front of Elena. He is, of course, wearing the ring that protects him from being killed by supernatural beings, and recovers in the presence of Rebekah. Elena decides that she is going to kill Katherine.