In a chilling social experiment, eighty American employees arrive for another ordinary day at the Belko Corporation's remote office in Colombia, only to find themselves trapped inside the fortified building. A mysterious voice over the intercom announces a deadly game: they must kill a specified number of their colleagues, or be killed themselves. As panic erupts, the staff fractures into factions. The compassionate everyman John Gallagher Jr. clashes with the coldly pragmatic COO Tony Goldwyn, while others, including the resolute Melonie Diaz and the sardonic maintenance worker Michael Rooker, struggle to survive the escalating chaos. Directed by Greg McLean from a script by James Gunn, this intense thriller forces a group of ordinary people to confront their most primal instincts in a pressure cooker of paranoia and violence, questioning how far anyone will go when the rules of civilization are stripped away.