Pretty Little Liars is prepared to celebrate Halloween early.

The ABC Family drama - which recently got renewed for Season 4 - airs "This is a Dark Ride" on October 23, its annual holiday standalone installment that serves as a nice appetizer before the main course of returning episodes in January.

This time around, the girls find themselves at a train-based party. One with poison on the menu? Watch this sneak peek and see why we ask:

Adam Lambert will also guest star/perform. Check out the American Idol runner-up in fang-based action now

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