Ready to test your skills, Pretty Little Liars fans?

This sneak peek photo is from the highly anticipated Season 2 finale (Episode 25: “UnmAsked”).

Can you guess (or remember!) who's chatting it up with Spencer (Troian Bellisario) at the masked ball in a pretty purple dress? Is it one of the Liars, or someone else?

Credit: Eric McCandless/ABC Television Group © 2012 Disney Photo: Guess Who: Spencer and ? in the Finale

Click here to see the original photo and learn the answer!

Pretty Little Liars airs Mondays at 8 p.m. ET/PT on ABC Family.

Get your Pretty Little Liars fix: Like us on Facebook and Follow us on Twitter and Tumblr!