Each protagonist faces individual challenges that "A" exploits throughout the 22-episode season:

The first season of premiered on June 8, 2010, on ABC Family/Freeform . It introduced the world to the affluent but secret-filled town of Rosewood , Pennsylvania, where the lives of four estranged friends— Aria , Spencer , Hanna , and Emily —are upended one year after their group leader, Alison DiLaurentis , mysteriously disappeared during a sleepover . The Core Mystery: Who is "A"?

The season centers on a relentless, anonymous blackmailer known only as . This figure begins sending the girls cryptic and threatening messages containing secrets that only the missing Alison could have known. Even after a body—initially believed to be Alison’s—is discovered buried in her former backyard, the messages continue, forcing the four "Liars" to reunite to uncover "A's" identity and the truth behind Alison's fate. Key Characters & Season 1 Arcs

Pretty Little Liars Part 1 (TV). (Contains spoilers) - Bookmarkedd