A woman (Dakota Fanning) gets trapped in a forrest and has to hide at night in a concrete bunker with three other people to avoid the creatures that come out at night. As they try to find a way to escape the creatures and the forrest they discover more about the person who built the bunker and the nature of the creatures. The first two thirds has the suspense in the forrest and the bunker whilst the last third revolves around explaing what and who the creatures are.