Haunted was the 7th episode of Season 1 of The Vampire Diaries and aired on October 31, 2009 ~ Halloween.
The show revolted around Vicki learning the ropes of being a vampire. There was a school Halloween Dance/Party that she went too. Elena was trying to protect Jeremy and Stefan was trying to help Vicki and watch over Elena. This episode shows Stefan killing Vicki by staking her when she was attaching Elena (first time they showed Stefan killing on the show).