65,000,000 years ago, a mountain-sized meteor crashed into the Earth in what is now the Yucatán Peninsula in Mexico, with a major chunk of the object landing in Uganda. The impact and resulting ecological catastrophe causes the Cretaceous–Paleogene extinction event. In present day, wealthy industrialist John Greystoke has been funding an expedition into the jungles of East Africa to locate the meteor, now a legend, and harness its unique energy. Despite the best efforts by scientist and adventurer James Porter, the expedition is a failure, and John is preparing to leave Africa with his wife, Alice, and their son, John Jr.