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 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 reveals she became "A" to take revenge on the girls for "stealing" Hanna's friendship from her.

Pretty Little Liars season 2, episode 25, titled "UnmAsked," is the series' second season finale, which originally aired on ABC Family on March 19, 2012. The episode is highly regarded by fans for its shocking reveal and intense action, often cited as a pivotal moment in the show's history.

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.

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.