Alison, Spencer, Aria, Hanna and Emily are four best friends. But when Ali goes missing on thier slumber party all hell breaks loose. The girls get mysterious text messages of a blocked number, 'A'. They are pretty sure Ali is 'A' until Emily's friend's mom finds Ali's decased body in her backyard. Now 'A' has gotten more mysterious then ever, because he, or she knows all thier secrets that only Ali knew. Little do they know that Ali's 'murderer' will strike agian. What will the Pretty Little Liars do when they find themselves sinking deeper into 'A's plan?

Four girls whose clique falls apart after the disappearance of their queen bee, Alison DiLaurentis. One year later, they begin receiving messages from a mysterious figure using the name "A" who threatens to expose their secrets. At first they think it's Alison herself, but after she is found dead, the girls realize that someone else knows their secrets, â€" including long-hidden ones they thought only Alison knew.