A Pretty Little Liars search party will soon be underway.

ABC Family has released a new promo for its upcoming Halloween special, "Grave New World," and it emphasizes the quartet's desperate trek to track down a possibly alive Alison. Will they locate their friend before it's too late?

Look for Aria, Emily, Hanna and Spencer crash the Ravenswood Founders Day Celebration on the installment, with Ezra continuing to lurk in the shadows and A "closer than the girls realize," according to a network press release.

Watch the teaser now and tune in October 22 for this special and also for the premiere of Ravenswood:

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.