Nora is a reclusive crime writer, content with the routine of life in her apartment in London. She hasn't seen her friend Clare in years - not since Nora walked out of school one day and never went back. So she's surprised to receive an invitation to Clare's hen do. Perhaps it's a chance to reconnect with her best friend. But something goes terribly wrong in the eerie glass house deep in the English countryside. Then Nora wakes up with her head bandaged and a police guard outside her door. Are they there to protect her - or arrest her? Nora is scared. Scared because while she can remember the broken glass, the gun, the blood, she's not sure if she can bear the full truth of what happened.