Most historians study small slivers of time, emphasizing specific dates, individuals, and documents. But what would it look like to study the whole of history, from the Big Bang through the present day, and even into the remote future? How might that change how we perceive the universe, the earth, and our very existence? A cofounder with Bill Gates of the Big History Project, David Christian set out to answer these questions when he took this wild ride through the entire 13.8 billion years we've come to know as "history." By focusing on defining events (thresholds), major trends, and profound questions about our origins, Christian exposes the hidden threads that tie everything together—from the creation of the planet to the advent of mankind, agriculture, and nuclear war.