The Vampire Diaries - Season 2 Episode 15 -

After confirmation by a terrified Katherine that the single ash-bound knife can kill an original vampire, Damon invites Elijah to a dinner party to stab him. Alaric finds out a nasty limitation to that method. Meanwhile, Stefan tells Elena about the time when he was a vicious vampire, Damon tries to do right, and John Gilbert plays a surprisingly positive part. Jeremy can't prevent 'immature' witch Bonnie from being questioned and suitably punished by accomplished Luka.