
Hanna Marin: Hanna is the bubbly, strong, and fierce "it-girl" of the group following Alison's disappearance. Spencer Hastings: Spencer is a headstrong, intelligent, overachieving girl who comes from the wealthy Hastings family and is usually forced into winning everything. The series has many characters, most of them recurring. The books progress with the four girls trying to figure out the identity of "A" and facing many dangerous obstacles and twists as they do so. Shortly after the messages begin, Alison's body is discovered buried in her yard.

"A" threatens to expose their secrets, including long-forgotten ones they thought only Alison knew. Three years after her mysterious disappearance, the girls begin receiving intimidating messages from an anonymous character named "A". Set in the suburbs of Philadelphia, the series follows the lives of four teenage girls nicknamed the Pretty Little Liars or simply the Liars, whose clique falls apart after the disappearance of their queen bee leader, Alison DiLaurentis. The series is loosely divided into arcs, chronicling the introduction and reveal of each " A". The franchise has been licensed by 's Kindle Worlds range of non-canon ebooks. The series spawned a media franchise with a television series adaptation loosely based on the novels which debuted on June 8, 2010, on ABC Family. The novels appeared on The New York Times Best Seller list for 62 weeks. Beginning with 2006's initial novel of the same name, the series follows the lives of four girls- Spencer Hastings, Hanna Marin, Aria Montgomery and Emily Fields.

Pretty Little Liars is a series of young adult novels by Sara Shepard.
