Paige throws Emily a surprise birthday party with even more surprising guests -- Jenna and Shana. But it's the actions of "A" at the party that lead to the biggest shock of all. Mona's selfless act provides Hanna and her mother with their first bit of good news, but it sends Mona down a familiar path. And Ezra gets some distressing news from Maggie regarding her and Malcolm. Meanwhile, Aria and Jake continue trying to define their confusing relationship. And Emily meets with a world-class coach in the last-ditch effort to salvage her swimming career.
