Conversation so far:
what episode does klaus come in vampire diaries
Know Thy Enemy
when did Know Thy Enemy from The Vampire Diaries air
Know Thy Enemy originally aired on April 7, 2011.
what season was Know Thy Enemy on The Vampire Diaries from
Know Thy Enemy is the 17th episode of the second season of The Vampire Diaries.

Question: who wrote it
Self-contained rewrite: who wrote the episode Know Thy Enemy from The Vampire Diaries