Mona reveals she became "A" to take revenge on the girls for "stealing" Hanna's friendship from her.
The episode centers on the Liars (Aria, Emily, Hanna, and Spencer) learning the true identity of the main tormentor, "A." It is revealed that Mona Vanderwaal is A. [S2E25] Unmasked
The episode features a masquerade party, and it ends with the discovery of a body believed to be Maya St. Germain, causing a major cliffhanger for the next season. Mona reveals she became "A" to take revenge
Mona tricks Spencer into going to a cliff-side "A's" lair (near a hotel area). Mona tries to force Spencer to join her "A Team," and when Spencer refuses, a struggle ensues. " and when Spencer refuses