9. The Sequel
While Identity Crisis is a murder mystery at heart there where far-reaching repercussions for the DC universe as a whole and the Justice League in particular.
The book would lay the foundations for Infinite Crisis, a storyline that would dominate the entire company within a couple of years. It did this by offering connective tissue between events long past and their ramifications in the present day.
After various villains learn the secret identities of the Justice League during the Silver Age, Zatanna's magic is used to erase that knowledge from their minds. In the sixties and seventies such actions would have been viewed as little more than putting the toys back in the box, but through modern eyes, it raised all kinds of ethical questions.
Before Infinite Crisis, Alan Heinberg and Geoff Johns wrote a sequel to Identity Crisis called Crisis of Conscious. The story pitted the League against the Silver Age villains who had since had their memories restored. Crisis of Conscious looked at how the team could function if they could not trust their actions or intentions. It also made many forgotten, and often times silly, characters, look every bit as dangerous as Lex Luthor or the Joker.