In upstate New York, after a Leonid meteor shower, two adults and a boy retrieve three identical ovoid-shaped rocks from the site where a meteor came down--but the rocks are alien eggs. When they hatch they disrupt and completely change the lives of the three who find them. The hatchlings at first are dangerous, mindless, giant worms that kill for food, then they change into griffins that find the three hosts and enter them as symbiotes.