Crisis on Infinite Earths

This twelve-issue maxi-series brought together almost every DC character ever created and destroyed most of the alternate Earths. A must-have for serious fans, this title cleared up inconsistencies in DC continuity and provided an epic, bitter-sweet story to boot. Among the heroes who came to their final end were Supergirl, Dove, the Barry Allen Flash, and Immortal Man. The heroes and villains left after the crises settled in one merged Earth, allowing for more interaction between DC heroes in the future.

Unfortunately, the destruction of the alternate Earths created several new problems for DC, since the old stories that took place on them had to be explained or “retconned” (“retroactive continuity”) away. To this day, fans have trouble making sense of the post-Crisis timelines of star-spanning DC groups like The Legion of Super-Heroes. This eventually necessitated DC’s Zero Hour: Crisis in Time series, meant to clean up their continuity for good.