The DC All In saga explodes into a brand-new Free Comic Book Day flipbook! First up, the core-line DC Universe soars into Superman action with the dazzling debut of superstar writer Dan Slott alongside acclaimed artist Rafael Albuquerque! In this special zero issue installment of the forthcoming Superman Unlimited series, you will witness the prelude to the biggest Superman comic book adventure of the year, as well as an ominous new threat from the heavens that will change the course of Kryptonian life on planet Earth as we know it! Then, as the Absolute Universe expands, dark forces begin to gather in the shadows...forces that have been waiting a very long time to shape events and seize control. All the while,a mysterious figure watches--but who is this powerful new character, and what do they want with Superman, Batman, Wonder Woman, and the rest of the emerging heroes?