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.

#1 New York Times bestselling series The fourth book in the #1 New York Times bestselling series that inspired the hit ABC Family TV show Pretty Little Liars.Four pretty little liars' charmed lives have turned into living nightmares. Emily's been shipped off to Iowa to live with her überconservative cousins. Aria's boyfriend is behind bars-because of her. Spencer's afraid she was involved in Ali's murder. But Hanna's fate is far worse: She's clinging...

#1 New York Times bestselling series The second book in the #1 New York Times bestselling series that inspired the hit ABC Family TV show Pretty Little Liars. In ultra-exclusive Rosewood, Pennsylvania, four beautiful girls are hiding very ugly secrets. Spencer covets her sister's boyfriend. Aria is fantasizing about her gorgeous young English teacher. Emily is infatuated with the new girl at school. And Hanna is using some ugly tricks to stay amazingly...

#1 New York Times bestselling series The fifth book in the #1 New York Times bestselling series that inspired the hit ABC Family TV show Pretty Little Liars. In idyllic Rosewood, Pennsylvania, four very pretty girls just can't help but be bad. Hanna will do anything to be Rosewood's queen bee. Spencer's digging up her family's secrets. Emily can't stop thinking about her new boyfriend. And Aria approves a little too strongly of her mom's taste in...

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.

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.

"It's spring break, and the pretty little liars are trading in Rosewood for a cruise vacation. They want nothing more than to sail into the tropical sunset and leave their troubles behind for one blissful week. But where Emily, Aria, Spencer, and Hanna go, A goes, too. From scuba diving to tanning on the upper deck, A is there, soaking up all their new secrets. Emily is smooching a stowaway. Aria's treasure-hunting partner is a little too interested...

Struggling to return to normalcy after surviving Alison's attempt to kill them, Spencer, Aria, Emily and Hanna endure a series of disasters before realizing that they are being stalked by a new "A" who knows all of their secrets.

In the weeks leading up to Ali's murder, Ali reveals her plots against Emily, Hanna, Aria, and Spencer, as well as a dark secret that has the potential to destroy everything.

Spencer, Hanna, Emily, and Aria are forced to watch as all their secrets finally come to light, from their littlest lies to their darkest deeds. Now, one by one, the girls' worlds come crashing down around them. Spencer gets kicked out of Princeton. Hanna gets kicked out of her dad's campaign--and his heart. Emily gets kicked to the curb. And Aria may get kicked out of the country. Thanks to me, these girls have lost everything--except their lives,...