From the Publisher:
OMAC robots are rampaging, magic is dying, villains are uniting, and a war is raging in space. And in the middle of it all, a critical moment has divided Earth's three greatest heroes: Superman, Batman and Wonder Woman. It's the DCU's darkest day, and long-lost heroes from the past have returned to make things right in the universe...at any cost. Heroes will live, heroes will die, and the DCU will never be the same again!
This omnibus colllects: Day of Vengeance #1-6, Day of Vengeance: Infinite Crisis Special #1, Rann/Thanagar War #1-6, Rann/Thanagar War:Infinite Crisis Special #1, DC Countdown #1, OMAC Project #1-6, Omac Project:Infinite Crisis Special #1, Wonder Woman #219, Villains United:Infinite Crisis Special #1, Villains United #1-6, Infinite Crisis Secret Files 2006 #1, Infinite Crisis #1-7.