Montana, 1876. Othniel Charles marsh, one of the two top palentologists in the world, is in the state's Judith River fossil beds, doing what he does best: digging up the bones of dinosaurs. Montana is a big state, but Marsh can't rest easy. Edward Drinker Cope, his biggest rival, and the other top paleontologist in the world, is also in the area, and there simply aren't enough bones for both of them, leading them to play dirty tricks. And time itself is against them: the fierce snows of winter are on the way and rumor has it, so is Sitting Bull, fresh from his triumph at little Big Horn.