When Klaus and Stefan roadtrip to Chicago, he undaggers Rebekah and his older sister Amity. The sister they never mention. Once they turned, Amity couldn't handle being a vampire, nor the blood on her hands. The dagger's appearance had been almost a relief. The family had all agreed a century had taken its toll on Amity, that she wouldn't survive eternity, and so they never removed the dagger. Not until Chicago, 2010.
Book 1
