They are everywhere. And no one knows where they come from. Journalist Martin Koller is in the hospital and cannot sleep. He is tormented by strange ringing in his ears that plunges him into a deep depression. The fact that his wife wants a child from him at all costs and that a young, ambitious colleague is meddling in his research on the far-right scene does not make things any better. Then he learns that his mother is dying. He gathers himself and makes his way back to the town of his childhood. For a few days, he is alone with his mother. Then they come, the visitors, and take over the whole house. They are everywhere: in the basement, in the rooms, in the attic. No one knows where they come from, no one knows what they want. A doctor whom Martin has known since his youth calls him; she has made a puzzling discovery. A nightmare begins.