'Pretty Little Liars' Season 4: I. Marlene King Reveals A Spoiler!

Queen of Hearts Pretty Little LiarsABC Family's "Pretty Little Liars" doesn't return for its fourth season until June 11, but executive producer and writer I. Marlene King is already revealing Rosewood's secrets.

Marlene took to Twitter today to spill a major spoiler about the upcoming season debut—namely, that the identity of a certain royal rabble-rouser will be unveiled!

"The Queen Of Hearts from the Halloween train will b unmasked in the premiere. U will be shocked to discover Shims identity! #PLLSpoiler," she wrote.

This is big news, indeed! You'll recall, the masked one wreaked plenty of havoc during the special, including drugging Aria and trying to throw Spencer off of the train! Hints throughout the episode indicated the Queen could actually be a King, but we're not ruling out anyone just yet.

Find out who she/he is when "Pretty Little Liars" returns June 11.

What are your theories regarding the Queen of Heart's true identity? Tell us in the comments and on Twitter!