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.
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.
Mona reveals she became "A" to take revenge on the girls for "stealing" Hanna's friendship from her. [S2E25] Unmasked
Authorities arrive, and it is discovered that Mona survived the fall. Dr. Sullivan diagnoses Mona with a personality disorder, and she is sent to a mental institution, Radley Sanitarium.
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. The episode centers on the Liars (Aria, Emily,
If you're looking for more details on a , character's reaction , or want to know what happens immediately after (in Season 3), I can provide that.
Spencer pushes Mona off the cliff during their fight. Mona reveals she became "A" to take revenge
The episode is renowned for its high-stakes tension and the "action-packed" nature of the reveal, marking a major turning point in the story.