Soon after the start of the 21st century, during construction on the London Underground, workers penetrate a cave and a huge dragon emerges from hibernation, incinerating the workers with its breath. The only survivor is a boy, Quinn Abercromby (Ben Thornton), whose mother, Karen (Alice Krige)—the project engineer—is crushed to death protecting him. The dragon flies out of the Underground, and soon more dragons appear. It is revealed through newspaper clippings and the narration that dragons are the species responsible for the extinction of the dinosaurs. They are speculated to hibernate after destroying most living creatures until the planet repopulates. Mankind's militaristic resistance, including nuclear weapons in 2010, only hastens the destruction, and by 2020, humans are nearly extinct.