ABC Family will continue its trend of having a Pretty Little Liars Halloween special this year.  The episode, entitled “Grave New World,” will see the girls crashing a Ravenswood costume ball. 

Decked out like the dames of Downton Abbey, Aria (Lucy Hale), Spencer (Troian Bellisaro), Hanna (Ashley Benson) and Emily (Shay Mitchell) set out on a search for Alison (Sasha Pieterse). They need to find her before a wrathful "A"—who may be a lurking Ezra (Ian Harding)—does. 



Leading up to the special will be an all-day Pretty Little Liars marathon beginning at 11 am EST.



“Grave New World” airs Tuesday, Oct. 22 at 9 pm EST. 



Photo credit:  ABC Family