Leah Hart is a normal teenage girl. That is until she meets Alison DiLaurentis. They become like sisters. When Ali disappears so does Leah. The only difference is Leah returns after a year. The day before Ali's body is found. Leah along with her friends Aria, Hanna, Emily and Spencer start getting messages from a person who goes by 'A'. But in the middle of all this drama two things will never change. Her friendship with the other girls. And her love for her best friends brother.