Pretty Little Liars was a TV drama staple during its 7-year run. The show follows a group of teenagers being viciously stalked and harassed by a mysterious figure known only as A. A's unique brand of taunts begins with blackmail about secrets that only their murdered friend Alison knew and progresses into acts of terror as new figures take up the mantle of A.
Source：https://www.cbr.com/shocking-a-schemes-pretty-little-liars/
