Newcomers to comic books sometimes find a huge task ahead of them. That makes sense seeing as there are decades of plots all intertwining, leading up to current issues. Among these storylines are major, crossover "crisis" events. Basically, they are the catalyst for huge changes across all of the DC releases. So, let's start to dig in with the first event summary. I'll post about the sequels, other, non-crisis events, and even major Marvel events later, too. I just hope this series gets at least one person to pick up the habit.
-Crisis on Infinite Earths
Running between 1985 and 1986, DC ran their first crisis event. The conception of this 12 issue series spawned from a desire to remove the idea of multiverses from the DC line, blending everything into a single universe in hopes that it'd make things easier for newcomers and thus boost sales.
After the run, everything was split into pre-crisis and post-crisis categories, and many household names had their stories essentially rebooted.
The general plot sees the villain, the Anti-Monitor, destroying various Earths while his counterpart, Monitor, calls for the DC heroes and villains to unite and stop the destruction. Time-travel and major battles follow. With the help of Spectre, Earth-Two's Superman, Kal-L, Earth-Three's Alexander Luthor, and Superboy of Earth-Prime defeat the Anti-Monitor and manage to bring peace to the unified universe. Those left on Earth have no memory of the events.
Note that, long before Game of Thrones kept killing off major characters, DC murdered hundreds of big names in this event. The Arrowverse is working toward an adaptation of this popular storyline, which is intriguing since Supergirl and Flash are two of the names that die in the comics.
You can purchase the graphic novel release of Crisis on Infinite Earths on Amazon here. Due to the importance and reception of the plot, there are numerous versions but you can do just fine with the base version.