As Alan Butler demonstrates in this extraordinary book, many key events in the history of our world--from the creation of the Moon to the evolution of human beings--came about through the intervention of humans from the future. Based on rigorous science, Butler's theory reveals the changes made by these time travelers, as well as the markers they left behind to prepare us for the most spectacular revelation of all: our first contact with our future selves, an event that will occur within the lifetime of most people alive today.