Second, if the North Atlantic drift were to shut down[broken anchor], that barrier would fail, releasing a flood of frozen air into the Northern Hemisphere, causing a sudden and drastic temperature shift.

Bell and Strieber contend that such destabilizations have occurred before, and cite seemingly impossible engineering feats by ancient civilizations which must have been catastrophically destroyed since they do not appear in the historical record.

Among their examples are the archaeological ruins of Nan Madol, which the book claims were built with exacting tolerances and extremely heavy basalt materials, necessitating a high degree of technical competency.

Interspersed with the analytical parts of the book are a series of interlinked short fictional scenarios, written in italics, describing what might transpire today if a destabilization of the North Atlantic Current were to occur.

Indeed, some events from the book are portrayed in the film with little modification, such as the failure of the Gulf Stream which freezes over large portions of the northern hemisphere including New York City.