A Nightmare on Sorority Row

 is the fourth episode of the seventh season of The Vampire Diaries and the one hundred and thirty-seventh episode of the series.

Summary
THE HORROR EVENT OF THE YEAR – Caroline has to organize Whitmore’s House of Evil and enlists the help of Stefan, Bonnie and a reluctant Damon. During the night, the event turns out to be scaring people too much. Enzo contemplates about his alliance with Lily while he connects with someone in a special way. As everyone tries to figure out what is going on, Matt goes down a vicious path. Meanwhile, Elena learns valuable details about the past.

Main Cast

 * Nina Dobrev as Elena Gilbert
 * Paul Wesley as Stefan Salvatore
 * Ian Somerhalder as Damon Salvatore
 * Kat Graham as Bonnie Bennett
 * Candice Accola as Caroline Forbes
 * Zach Roerig as Matt Donovan
 * Matt Davis as Alaric Saltzman
 * Michael Malarkey as Lorenzo

Special Guest Starring

 * Annie Wersching as Lillian Salvatore

Recurring Cast

 * Elizabeth Blackmore as Valerie
 * Jaiden Kaine as Beau
 * Scarlett Byrne as Nora
 * Teressa Liane as Mary-Louise
 * Tim King as Oscar
 * Luke Benward as William Duncan
 * Hunter Parrish as Andrew Montez
 * Madison Riley as Cleo Mitchell

Guest Cast

 * Todd Lasance as Julian (flashbacks)
 * Nico Tortorella as Whitmore College Student

Trivia

 * Oscar returns to the Heretics after a long time being away, apparently deliberate.
 * Caroline organizes Whitmore's House of Evil. Stefan, Bonnie and Damon help her prepare along with Matt, William and Cleo.
 * Matt, William & Cleo and Stefan, Bonnie & Damon attacked the Heretics seperately. The first trio attacked the Heretics in general, while the latter trio attacked Oscar.
 * Elena discovers that Marge is related to her.
 * Enzo is suspicous about Valerie. This leads him to confronting her about it. Lily has a talk with Valerie too about her past with Stefan.

Continuity

 * The Phoenix Stone is seen for the first time.
 * This is the second flashback episode in the season. It are closest flashbacks ever, because it takes place one month ago, right after the events in A Date With Destiny.
 * The first flashback episode in the season was the previous episode A Date With Destiny.
 * This is the fifth holiday episode in the series, and also the first one this season. This is the second Halloween episode; as such, this episode takes place on October 31, 2013.
 * The first holiday episode and Halloween episode was in Season One's Haunted.
 * The second was Christmas in Season Four's O Come, All Ye Faithful.
 * The third was Thanksgiving in Season Six's Fade Into You.
 * The fourth was Christmas in Season Six's Christmas Through Your Eyes.
 * The sixth was Christmas in Season Seven's Wrapped in Red.
 * The seventh was New Year in Season Seven's A Long Way Down.

Cultural References

 * The title is a pun on two slasher films from the 1980s:
 * "A Nightmare on Elm Street" is a 1984 American supernatural slasher horror film written and directed by Wes Craven, and the first film of the Nightmare on Elm Street franchise. Set in the fictional Midwestern town of Springwood, Ohio, the plot revolves around several teenagers who are stalked and killed in their dreams (and thus killed in reality) by Freddy Krueger. The teenagers are unaware of the cause of this strange phenomenon, but their parents hold a dark secret from long ago.
 * "The House on Sorority Row" is a 1983 American slasher film directed by Mark Rosman. The film has become a cult classic among fans of the genre.