Crisis on Multiple Earths 3 : Countdown to Crisis, Paperback by Conway, Gerry; Thomas, Roy; Busiek, Kurt; Perez, George; Wolfman, Marv, ISBN 1779521766, ISBN-13 9781779521767, Like New Used, Free shipping in the US

"When the walls of reality first fell, a heroic alliance between the Justice League of Earth-One and the Justice Society of Earth-Two was forged, beginning a saga that would transcend space and time! Now, bear witness to DC's original super-teams' final adventures across multiple Earths-final, that is, until they face a Crisis unlike any they could have ever imagined... A hero falls, and the only suspects are his closest allies! A mysterious disappearance brings our heroes to the wondrous New Genesis! Lex Luthor meets his most worthy ally-himself! In the rematch of the century, the Crime Syndicate of Earth-Three make their villainous return and bring the timeline to its knees! Explore the Multiverse with your favorite DC heroes as they battle foes new and old, traverse the cosmos, and defend justice on any Earth where it's threatened"--