Around 10,000 BC, the planet is sliding into a minor ice age, and the woolly mammoth and saber-toothed tiger are vanishing within a few thousand years. This film, produced by Gabriel Gornell and David Padrusch as a nonfiction companion to Roland Emmerich's 2008 feature, tracks the archaeologists and climate scientists piecing together what happened to them, and to the small bands of early humans then pushing into North America. CGI reenactments recreate mammoth hunts where killing a single animal, weighing close to ten tons, could mean the difference between a community eating through winter or starving, and the film stages the encroaching comet impact some researchers link to the extinction wave. Fieldwork at archaeological dig sites turns up fossilized bones, stone weapons, and traces of ancient dwellings, evidence the film uses to argue that the disappearance of the great mammals and the arrival of humans who depended on them for food and hides are part of the same story rather than a coincidence.