Following a parapsychology conference, Laura, J.J., and Celia return to their guests: Andrew, an obnoxious grad student; Gregory, an anthropologist; and Diane, Gregory’s wife and Laura’s longtime friend. On Laura’s desk is a strangely marked box that wasn’t there before. When Andrew opens the box it vanishes. And outside all the office doors and windows is a thick, mysterious fog. Gregory and Diane attempt to leave the office – and a moment later, Diane runs back in, bleeding and hysterical: in the fog is a monster that attacked her and killed Gregory. The phones are dead; Celia tries to get help via the computer link but the computer screen instead displays: “You have let me out. Find the box in one hour – or you must take my place inside.” But the box is nowhere to be found.