Anna's world is turned upside down after a mysterious couple tries to gain access to her apartment. Soon, she begins seeing them everywhere. At the same time, a series of loud banging noises keep emanating from the apartment behind hers. Are these incidents just a coincidence, or do they have something to do with the gruesome serial murders that begin to plague her town? It begins with a deceptive cry for help. Before it ends, a quiet Detroit suburb's illusion of safety will be shattered forever.