Sierra Parker was one of the 6 in Alison's group. She met Ali and the group in 8th grade, and was friends in the 8th and 9th grade. And during that time was when she was dating Ali's really hot older brother, Jason Dilaurentis. When Ali went missing, Jason and Sierra broke up and Jason and his parents moved away and out of Rosewood. Sierra was devastated and she then started drinking and doing drugs. She couldn't help it because of her break up. One year later, Sierra still drinks and does drugs, but not as much. But what will happen when Sierra and the other four girls get messages from -A? And most importantly, what will happen when Jason comes back to town? Read to find out...