Here's the official episode description for " Haunted " ( episode 7 ). Check Vampire Diaries episode 7 <= page for previously posted spoilers and changed air date!
HALLOWEEN IN MYSTIC FALLS
As Vicki’s behavior becomes more dangerous, Stefan tries to help her. Elena tries to convince Jeremy to stay away from Vicki.
Caroline gives Bonnie a necklace she took from Damon to wear with her Halloween costume, and when Damon tries to take it back, he is surprised by Bonnie’s abilities.
Bonnie discusses the incident with Grams and learns more about her family’s past. Trying to cheer Vicki up, Matt takes her to the high school’s haunted house, but the evening soon takes a terrifying turn.