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...

When one of their tightly-knit group mysteriously disappears, four high school girls find their friendship difficult to maintain when they begin receiving taunting messages from someone who seems to know everything about their past and present secrets.

Former best friends Emily, Aria, Hanna, and Spencer continue to live in fear as they struggle to keep hidden even more secrets and someone new begins stalking them via their cell phones.

After seeing a girl who looks just like herself in a violent video, Emma, who lives with a foster family, begins a search to find out what happened to the girl.

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.