Seventh graders Emily, Spencer, Aria and Hanna worship Alison in Sara Shepard's Pretty Little Liars. Alison’s the prettiest, most popular girl at Rosewood Day School. When the five girls are thrown together at their school’s charity drive, they quickly become friends. Over a year later, the girls are still friends, but the power Ali wields over them all has them feeling uncomfortable. She knows all of their deep, dark secrets: secrets that could ruin their lives if anyone else found out. When Ali disappears, the four girls are shaken, but also…relieved.
Three years later the girls start getting strange text messages, emails and notes from someone: someone who seems to know all of those secrets that they thought were safe since the disappearance of Ali. The messages get more and more threatening and the girls can’t help but wonder: Is Ali sending the messages? If not, then who?