Grave New World (Pretty Little Liars)

"Grave New World" is the 13th episode of the fourth season of the American mystery drama series Pretty Little Liars. It originally aired on October 22, 2013 on ABC Family and serves as the season's Halloween episode, which aired as part of the 13 Nights of Halloween programming block. The episode was directed by Ron Lagomarsino and written by Joseph Dougherty, Oliver Goldstick and I. Marlene King. The episode also serves as a backdoor pilot to the series’ spinoff Ravenswood, which follows a group of people investigating the supernatural occurrences in the titular town. As a result, the episode features the spinoff's main cast as guest characters and some supernatural elements.

In the episode, Aria, Emily, Hanna and Spencer attend the Ravenswood Founders Day Celebration party at the cemetery in hopes of tracking down Alison, who they believe is still alive and on the run from A. While there, the girls encounter a masked figure following their every move and unexplained supernatural occurrences. Meanwhile, Caleb meets Miranda, a girl in the foster system looking for her uncle, while on the bus to Ravenswood and helps her deal with some issues stemming from her past in the town.

"Grave New World" was watched by 3.18 million viewers and garnered a 1.4 rating, even with the previous episode and up from last year's Halloween episode. The Halloween special set ratings record for the 13 Nights of Halloween programming block and became the seventh episode of the series to amass over 1 million tweets. The episode garnered a lukewarm reception from television critics, who believe it fell flat from the summer finale and the last Halloween special. However, the final moment where Alison reveals herself was considered by most the best part of the episode.