Pretty Little Liars
Pretty Little LiarsFacebook/Screenshot

"Pretty Little Liars" spoilers have been promising a shocking summer finale for weeks, with the possibility of one of the main characters dying. And, on Tuesday, it finally delivered when Mona was killed off, rather brutally, by a blonde assailant.

But before Mona breathed her last, she managed to ring up Aria and expose one of Alison's lies regarding Bethany Young. Although Alison has been claiming to be unaware of who Bethany was, Mona revealed that it was Alison who lured Bethany to Rosewood, and that she knew about her mother's affair with Mr. Young. "Alison set her up. She was jealous, and she wanted Bethany dead," said Mona.

But before Mona could finally voice out her belief that Alison is "A," she was killed by a mystery blonde girl, and her body was last shown lying in the trunk of a car.

Mona's death is not surprising, as a number of "Pretty Little Liars" fans had predicted the same. Nonetheless, "RIP Mona" hashtag began trending on Twitter soon after the episode was aired.

"I just can't handle todays episode of #PLL is too much!! Mona is dead Spencer is in jail Ali is Crazy and she's A whaaat!? #RIPMona," one fan wrote. Another added: "What even?!?!? Mona being killed by A, thats very crazy. Just proves that no one is safe. My mind is definitely blown. #RIPMona."

Interestingly, showrunner Marelene King had expected fans to freak out as soon as the finale was aired, and she said as much in a recent interview with Entertainment Weekly.

"I hope fans enjoy the ride and exhale when it's over, take a moment, take a few breaths before you jump on social media and start freaking out."

On Mona's death, she said: "Whenever a beloved character or a character that fans appreciate dies, it shakes our world, and the fallout of this death is really what the show is about for the next 13 episodes, including Christmas."

"Pretty Little Liars" is set to return for a Christmas-themed special called "How the 'A' Stole Christmas," and season 5B will commence from January 2015.