Radley Sanitarium has given Mona a clean bill of health and she is headed back to the halls of Rosewood High, much to the girls' dismay. With their former tormentor now back in their everyday lives, Aria, Emily, Hanna and Spencer take very different views of the new Mona. She made their lives a living hell…. Could she really be cured? And what other secrets could she be holding onto?It's up to Mona to prove to the girls if she has changed or not.