All of reality comes under attack when a mysterious force of entropy begins slowly erasing time itself—making its way from both the past and future toward the present! As history itself unravels around them, the heroes of the world–including Superman, Batman, Wonder Woman, The Flash, the Justice Society and the Titans—scramble to fix the broken time stream. But even if they stop the true source of the chaos, the world they save will never be the same! Collects ZERO HOUR #0-4 in hardcover for the first time. Includes a new introduction by Dan Jurgens, updated timeline to the DC Universe and never-before-collected bonus material.