Credit: ABC Family

Big news, Pretty Little Liars fans: Not only will we find out who/what is in the trunk in the Season 4 premiere, but the Queen of Hearts’ identity will also be revealed during the hour!

On Wednesday, May 29, showrunner Marlene King tweeted, “The Queen Of Hearts from the Halloween train will b unmasked in the premiere.  U will be shocked to discover Shims identity!”

PLL fans may remember The Queen of Hearts as the character who terrorized Aria on the Halloween train, and based on Marlene’s previous tweets, the enigmatic figure is someone we’ve already met. As for Marlene’s use of the word “Shims,” don’t jump to conclusions and assume she’s talking about Lucas (who Mona called “shim”). In fact, “Shim” is a word the PLL Powers That Be use to refer to “A.”

Back in December, PLL producer Lisa Cochran-Neilan told Wetpaint Entertainment, “You know, ‘A’ has always been very, very elusive. We refer to “A” as Shim, as in she/him/it.”

So who could “shim” be? Whoever it is, it seems they wanted the Liars dead, as members of the "A" Team (or Red Coat? Or the "B" team? We’re not sure!) nearly succeeded in killing Aria on that train!

Who do you think the Queen of Hearts might be? Tell us below!

Pretty Little Liars Season 4 premieres on Tuesday, June 11, 2013 at 8 p.m. ET/PT on ABC Family.