After a series of portentous dreams, Richard Moss is drawn to a secluded spot in Ashdown Forest. He witnesses a spacecraft landing and is taken to a distant planet called Terra Nova where inhabitants of Earth migrated 5,125 years ago. Terra Nova is ruled by a 'Great Leader' named Ezra who oppresses his people. Richard is imprisoned but then rescued by a cosmonaut named Noah and he joins the resistance, forcing Ezra out of power.Richard learns he was brought to Terra Nova to equip him to return to Earth to help avert a similar disaster recurring there. He hears a Mayan prediction of an impending cataclysmic event as another cosmic cycle of 5,125 years is about to end. A deadly asteroid is heading for Earth which will lead to the extinction of its inhabitants unless a way can be devised to divert it.