After their recent encounter with �A�, Aria, Emily, Hanna and Spencer think they may be closer than ever to figuring out whom �A� really is. But when the girls decide to enlist Caleb�s hacking skills to help with their quest, Hanna no longer wants a part of the plan. The last thing Hanna wants is to get Caleb involved in something else shady and also to open the door to questions that Hanna can�t answer. Once the girls realize that �A� has a helper, Hanna has no other choice. Instead of focusing on figuring out who the �helper� is, Hanna decides to put all of her efforts into throwing a surprise party for Caleb. But will a surprise party at Spencer�s lake house be the diversion Hanna is looking for, or just a recipe for disaster?

Meanwhile, Aria and Ezra must deal with the aftermath of coming clean.