The CRISIS begins here! Before DC's first reboot in 1985, a multiverse existed where each "Earth" had its own team of superheroes. Earth-1 had the Justice League, Earth-2 had the Justice Society, so on and so forth. Once a year, the boundaries between these worlds would become thin, and the Justice League and Justice Society would team up to fight crime on other Earths! This annual event showcased first appearances of major villains like the Crime Syndicate, altered continuity with Black Canary and Red Tornado joining the Justice League, and set the stage for the multiverse-shattering reboot Crisis on Infinite Earths!