Documentary investigating the greatest vanishing act in the history of our planet - the sudden disappearance of the dinosaurs 66 million years ago. Experts suspect that the dinosaurs were wiped out after a city-sized asteroid smashed into the Gulf of Mexico causing a huge crater. But until now, they haven't had any proof. In a world first, evolutionary biologist Ben Garrod joins a multi-million pound drilling expedition into the exact spot the asteroid hit to get evidence of the link. Paleopathologist Professor Alice Roberts meets top scientists and has exclusive access to a mass fossil graveyard believed to date from the same time the asteroid hit. Alice treks across the plains of Patagonia to see if the effects of the asteroid impact could have wiped out dinosaurs across the world. Alice and Ben's investigations reveal startling new evidence of a link between the asteroid and the death of the dinosaurs, presenting a vivid picture of the most dramatic 24 hours in our planet's history.