In the near future, two convicts (a disgraced senator and her husband) are sentenced to twenty-five years in a cryogenic penal facility for a horrible crime they claim they didn't commit. When the prison malfunctions, accidentally releasing all of the prisoners, the escapees discover that they've been incarcerated for thousands of years and are now the only survivors of a global catastrophe that wiped out all of mankind, an event so devastating that prehistoric creatures now walk the Earth once more.