The book proposes a catastrophic theory for the end of the last ice age, suggesting that the Earth was struck by a comet, causing widespread destruction and upheaval.Donnelly was an American politician, lawyer, and writer, who had a keen interest in ancient history and mythology. In "Ragnarok," he draws on a range of sources, including scientific evidence, ancient myths, and geological data, to argue that the Earth was once hit by a comet, which led to a global catastrophe that destroyed much of civilization at the time.The book presents a detailed analysis of the evidence supporting Donnelly's theory, including geological evidence of widespread floods, the presence of comet fragments in various locations around the world, and ancient myths and legends describing catastrophic events.While Donnelly's theory has been largely discredited by modern science, "Ragnarok" remains a fascinating and thought-provoking work, offering a unique perspective on the ancient history of the Earth and the possible causes of past global catastrophes.