When their best friend Alison mysteriously vanishes, four girls believe their secrets are safe forever. But when they begin to receive threatening messages from someone namedA, the truth may be only one text away. Filled with mystery, scandal, intrigue and nail-biting suspense, Pretty Little Liars is based on the best-selling book series for young adults from Alloy. Set three years after the disappearance of Alison, the manipulative and vindictive queen bee, it revolves around her four 16-year-old girlfriends Aria, Emily, Spencer and Hanna who have lost touch with one another until each begins to receive mysterious messages suggesting that Alison is watching them and knows every secret they are desperate to keep. Even after Alison's body is discovered, the messages don't stop...