The story of the discovery of a remarkable new fundamental law of nature -- the law of universality -- which is the biggest new idea in science since chaos and complexity. The law of universality at last explains why a vast range of totally unpredictable, cataclysmic events happen -- and why they are inevitable -- from major earthquakes and forest fires, to mass animal extinctions, and even events that are dependent on human behavior, such as stock market crashes, massive traffic jams, the wild-fire spread of fashionable ideas, and the outbreak of major wars. The search for the causes of these events has baffled all who have studied them. Now the law of universality shows that all of these events share one fundamental underlying cause: all of them happen in densely packed networks, whether networks of faults in the earth's crust, of trees in the forest, or of human beings, and in any such network eventually the network will reach a "critical state" and a huge tumultuous upheaval is guaranteed to occur, though exactly when it will happen is totally unpredictable.Buchanan explains how this discovery will revolutionize our understanding of the causes of the major events that shape our lives and empower us to better manage our efforts to control and predict catastrophic events of all kinds.