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.

After their friend Alison, missing for more than three years, turns up dead, four former best friends, each of whom had a secret known only by Alison, begin receiving frightening messages from someone identified by the letter "A."

"Sutton Mercer had the perfect life, great friends, and a gorgeous boyfriend...until someone murdered her. Then the killer forced Sutton's long-lost twin sister, Emma, to pretend to be her. Now Sutton can only watch from beyond the grave as Emma frantically tries to figure out who killed her sister, and why. But when Sutton's body is discovered, Emma's time is up--and she becomes the number-one suspect herself."--Publisher's statement on Amazon.com....

"My friends and I used to play lying games. Now my twin sister is living one. When I was alive, my family seemed picture-perfect. My adoptive parents adored me, and my little sister, Laurel, copied my every move. But now that my long-lost twin, Emma, has taken my place to solve my murder, we're both learning just how flawed my family really is. Laurel is shooting Emma nasty looks and sneaking around with my ex-boyfriend. And it turns out my parents...

"Four teens who met on an online cold-case solving forum attempt to solve another teen's murder"--

Ava, Caitlin, Mackenzie, Julie, and Parker are all driven to be perfect--no matter the cost. At first the girls think they have nothing in common, until they discover that they all hate the same person: handsome womanizer Nolan Hotchkiss, who's done things to hurt each of them. They come up with the perfect plan to murder Nolan--jokingly, of course. They'd never actually go through with it. But when Nolan turns up dead in the exact way they'd discussed,...

High school seniors Aria, Emily, Hanna, and Spencer have all done horrible things -- things that would put them behind bars if anyone ever found out. And their stalker 'A' knows everything. So far A has kept their secrets, using them to torture the girls. But now A's changed the game. Suddenly the girls are hauled in for questioning, and all their worlds begin to unravel. If A's plan succeeds, Rosewood's pretty little liars will be locked away for...