Alison, Spencer, Hanna, Aria and Emily are best friends. Even though they're the most popular girls in school, Alison gets all the attention. At one sleepover, after all the girls told each other their most precious secrets, Alison goes missing. A year later, Alison's dead body is found - but at the funeral, Spencer, Hanna, Aria and Emily each get a text from "A", who wants to expose their secrets that only Alison could possibly know. Is Alison "A"? Is she really alive? Will they be able to keep their secrets? Starring: Sasha Pieterse (Alison), Troian Bellisario (Spencer), Ashley Benson (Hanna), Lucy Hale (Aria) and Shay Mitchell (Emily).