After their friend who has been missing for more than three years turns up dead, four former best friends continue to receive frightening messages from someone who knows damaging secrets about them.

After high school juniors Spencer, Emily, Hanna, and Aria think they have seen Ali, their missing and presumed dead friend, they pursue clues from a mysterious stalker, trying to find out if she is still alive.

Hanna, Spencer, Emily and Aria are trying to move on and forget about their old friend Alison DiLaurentis and all the torture she put them through, but someone is trying to keep her spirit alive.

Former best friends Hanna, Aria, Spencer, and Emily, who lost their best friend and leader, Alison, years ago when she disappeared, find themselves in grave danger when they pursue the truth about Alison.

On trial for murdering an actually still-alive Alison DiLaurentis, only Aria, Emily, Spencer, and Hanna know they have been framed and resolve to beat Ali at her own game.

"It's springtime in Rosewood, but while everyone else is searching for the perfect prom dress, Hanna, Spencer, Emily, and Aria are on a different kind of hunt: They're looking for A...Hanna puts her campaign for prom queen on the back burner to volunteer at a burn clinic, where one of A's victims is recovering. Emily digs into Ali's past at the mental hospital with some very crazy consequences. Spencer contacts an amateur private eye to help her stalk...