Colorado Parks & Wildlife Research Library

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.

After their missing friend's body is found and another of their friends commits suicide, four former best friends live in fear of their secrets being exposed by someone who is stalking them via their cell phones.

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.

Four girls living in a wealthy suburb discover the identity of a stalker who has been sending them shocking text messages, and uncover the mystery of who killed their childhood friend.

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.

The four former best friends try to overcome their friend Ali's murder, but become alarmed when they receive text messages from the mysterious "A" and learn that their friend's accused killer has been released from jail on bail.

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.

In picture-perfect Rosewood, Pennsylvania, ash-blond highlights gleam in the winter sun and frozen lakes sparkle like Swarovski crystals. But pictures often lie-and so do Rosewood's four prettiest girls. Hanna, Aria, Spencer, and Emily have been lying ever since they became friends with beautiful Alison DiLaurentis. Ali made them do terrible things-things they had to keep secret for years. And even though Ali was killed at the end of seventh grade,...

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.

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.