When Louise Williams receives a message from someone left long in the past, her heart nearly stops. Maria Weston wants to be friends on Facebook. Maria Weston has been missing for over 25 years. She was last seen the night of a school leavers' party, and the world believes her to be dead. Particularly Louise, who has lived her adult life with a terrible secret. As Maria's messages start to escalate, Louise forces herself to reconnect with the old friends she once tried so hard to impress. Trying to piece together exactly what happened that night, she soon discovers there's much she didn't know. The only certainty is that Maria Weston disappeared that night, never to be heard from again - until now.