WARNING: The following article contains spoilers for Detective Comics #1016, by Peter J. Tomasi, Doug Mahnke, Tyler Kirkham, Keith Champagne, Christian Alamy, Mark Irwin, David Baron and Rob Leigh, on sale now.
In the latest storyline of Detective Comics, longtime Batman villain Mr. Freeze was finally, after all this time, able to accomplish his goal: awaken his wife from her cryogenic sleep and save her life from the sickness that had taken her over. Lex Luthor (who is currently in his Apex Predator form thanks to Perpetua, the Mother of the Multiverse), approached Freeze and, in a bid to tip the cosmic scales of the world in favor of doom, offered him what he always wanted: a serum that allowed Victor to reanimate and cure Nora.
However, Lex's so-called cure came with side-effects. Yes, Nora is awake and physically healthy, but her mind is deteriorating. With a body now as cold as her husband's and ice weapons that make her a dangerous threat, the new Mrs. Freeze has gone solo. Leaving her husband behind, Nora is out to make a name for herself by terrorizing the residents of Gotham City -- and she's growing more and more unstable.
But it turns out Luthor may have always known something like this could happen. Why? Because the serum he gave Mr. Freeze wasn't new. Luthor used it back in Forever Evil... to create Bizarro.
Forever Evil was a villain-centric event by Geoff Johns and David Finch published in 2013 as part of DC's New 52 continuity. In it, Lex Luthor took on a leading role as the world's only hope when the Justice League mysteriously disappeared and the villainous Crime Syndicate (an evil version of the Justice League from Earth-3) began to rule the planet with an iron fist. Luthor worked alongside Batman and put together a team of villains to fight back. One of the members of his band of misfits was Bizarro, who received a new origin in the event.
Subject B-0, as he was called, was created by Luthor in an attempt to clone Superman. Unfortunately, the experiment was less than successful and the villain ended up creating a greying, twisted version of the Man of Steel. Part of this experiment involved a serum -- the very same serum Luthor gives to Victor Fries to bring his wife back to life.
Even though Freeze says he ran a check on the serum, it still had a negative effect on Nora. The serum, combined with his own experiments, is now what is plunging Mrs. Freeze into villainy. Worse still, her condition will only continue to devolve. This means that not only will she get more dangerous, she might become more powerful if she transforms into a Bizarro version of herself.
As the issue comes to an end, Victor is back behind bars and his wife is on the run. Now, she is free... and a total freezing menace.