Warning: This post contains spoilers for Harley Quinn #49.
Harley Quinn isn't a supervillain anymore, but she's putting the entire DC Universe in danger in ways most villains can only dream of. In a case of the comic universe overlapping with film, Harley may be holding the fate of DC in her hands... literally.
After Harley Quinn #49 ends with her decision to read a comic book altering the continuity of the universe (and alerting Continuity Cop to the situation), the true damage inflicted to the fabric of DC's reality may continue to be played out in the next several issues of the main Harley Quinn comic.DC comics universe looks like it will be resting in her hands over the next few issues of Harley Quinn, after
Existential threat or not, it's impressive, considering most of the issue is dealing with something else entirely. Harley's tussle with the unkillable Lord Death Man - and the reveal that he's secretly completely infatuated with her romantically - ends simply enough. By the end of the issue, she hasn't managed to kill Lord Death Man, but she has managed to convince her client that she threw him in a volcano, so she gets paid and all's well that ends well... until Harley decides to relax with a comic book, and breaks the universe in the process.
Harley doesn't mean to break the universe, she just wants to take a little down time and do some reading. But as she picks up the comic (which just so happens to be Harley Quinn #50), it starts making some interesting 'shing' noises and her hands start to glow. Somewhere else in the DC universe, Jonni DC (aka Continuity Cop) hears the noises, and rushes out into the street to find out what is damaging the DC world. Before her eyes, the fabric of DC reality warps: from the Flash becoming an elephant, to Batman becoming President.
The issue ends with Jonni declaring that Harley must be stopped, and a promise that next week 'Harley Quinn Destroys DC Continuity'! Jonni DC is an extremely minor character who is a force in the DC universe, charged with making sense of the various continuity altering events that tend to happen in the world of comics. In this issue, she even references still dealing with the fallout from Future's End, and although she hasn't had many appearances, it seems that she's always been in the background, dealing with errors. And of course, Harley is known for being one of the few characters of this world that breaks the fourth wall, so setting her up against someone like Jonni DC seems like it will be a perfect fit.
It's not yet clear quite how far the ramifications of Harley's comic-reading, continuity-destroying actions will go, but this is set to be a short story arc without major crossovers, so it's likely that Harley (and Jonni) will quickly be able to fix the issue and set things back to rights. However, there's a strong possibility that while this won't have a huge effect on the rest of the DC universe, it may have some long term impacts on the characters that are closest to Harley Quinn...
Harley Quinn #49 is now available from DC Comics.