Elena Gilbert will learn a valuable lesson on this Thursday's episode of The Vampire Diaries: you can't clean the crazy away.

Following her first kill, viewers will watch the new blood sucker suffer through some hallucinations - that's what happens when you off a hunter, Klaus says - on "We All Go a Little Mad Sometimes," a condition that won't leave her alone in the shower.

It will only get worse, in fact. See what we mean in this sneak peek at the upcoming installment:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.