This episode is famous for introducing the of the show. The studio filled with life-cast masks shifted the tone from a standard teen drama to a psychological thriller. It also set the stage for the introduction of "Red Coat" and the eventual "A" reveal.

The "Pretty Little Liars" episode titled (officially Season 4, Episode 4, often labeled by file-sharing groups as 404 hdtv-lol ) is a pivotal chapter in the mystery of the "A" Team.

: This indicates the source of the video was a High-Definition television broadcast (in this case, the ABC Family network).

The episode first aired on , and centers on the Liars digging into the past of Ali’s mysterious masks. 🎭 The Central Plot: The Mask of Ali

: This is the name of the "release group" that originally encoded and uploaded the file to the internet. 404 : This represents Season 4, Episode 04. 💡 Why This Episode Matters

: Aria and Hanna find a porcelain mask that looks exactly like Alison.

Emily is struggling with a shoulder injury that threatens her swimming career.

The girls discover a link between Alison DiLaurentis and a local mask maker, Hector Lime.