The original show, which had Marlene King at the helm, starred Lucy Hale, Ashley Benson, Shay Mitchell, Troian Bellisario and Sasha Pieterse as a group of Pennsylvania teenagers being hunted - largely via text message - by a mysterious figure known simply as `A.` (And eventually as `AD` in the show's later seasons.) The series is based on young-adult books written by Sara Shepard.
In addition to airing for seven successful seasons on ABC Family/Freeform (2010-2017), Pretty Little Liars also birthed two short-lived spinoffs - Ravenswood, which aired from 2013 to 2014, and Pretty Little Liars: The Perfectionists, which aired from March to May of 2019. The latter also drew inspiration from The Perfectionists, another book series by Shepard.