Pretty Little Liars is an American mystery teen drama television series created by I. Marlene King, which aired on Freeform from June 8, 2010 to June 27, 2017, based on the novel series of the same name written by Sara Shepard, lasting 160 episodes over seven seasons. Set in the fictional Rosewood, Pennsylvania, the plot follows five best friends whose secrets are consistently threatened by the anonymous "A", who begins harassing them after the disappearance of their clique leader. Troian Bellisario, Ashley Benson, Lucy Hale, Shay Mitchell, Sasha Pieterse, and Janel Parrish lead the ensemble cast, alongside Holly Marie Combs, Ian Harding, Bianca Lawson, Laura Leighton, Chad Lowe, Nia Peeples, Tyler Blackburn, and Andrea Parker.