Spencer stole her sister's boyfriend. Aria is brokenhearted over her English teacher. Emily likes her new friend Maya . . . as much more than a friend. And Hanna's obsession with looking flawless is literally making her sick. But the most horrible secret of all is something so scandalous it could destroy their perfect little lives.
And someone named "A" is threatening to do just that.
At first they thought A was Alison, their friend who vanished three years ago . . . but then Alison turned up dead. So could A be Melissa, Spencer's ultracompetitive sister? Or Maya, who wants Emily all to herself? What about Toby, the mysterious guy who left town right after Alison went missing?