As none of us have much of it, let’s cut to the marrow: this is a book about time as understood through the equations of special and general relativity. So it’s to do with frames of reference, the speed of light, and lines of causation. It’s not a philosophical history of time, still less a mythical or religious view. But if you want a clear and concise formulation of what Einstein’s equations tell us about time within the constraints of relativity, then this is your book.