SPOILER WARNING: This article contains spoilers for Justice League of America #7, on sale now.
The Justice League of America's resident scientists embark on a research mission / first date in Justice League of America #7 by Steve Orlando and Jamal Campbell, as the Atom and Killer Frost prod a baby frozen in a glacier for genetic clues to cure Frost's "heat sickness" that compels her to consume warmth from other living things. But their research proves fruitless, and an attack from an all-but-forgotten villain serves as a harbinger of darker days to come.
Still, Ryan Choi and Caitlin Snow have excellent… chemistry.
Ice Ice Baby
In an effort to help his new teammate and further the cause of science, Ryan pulls some strings with Manhattan's Museum of Unnatural History to gain access to the Dorrance Glacier Boy, whose frozen state bears many signs that in fact the eponymous glacier grew around him. The Atom believes the baby may have had cryokinetic powers like Frost's and, if so, that his DNA may include clues to curing her.
This ultimately proves a dead end -- at least for now -- but serves as a key moment of bonding for Ryan and Caitlin, who clearly have feelings for each other. Killer Frost admits as much to Black Canary later in the issue during a sparring session, but says she can't risk getting close to him until she can cure, or at least more reliably manage, her sickness of stealing heat.
Longtime fans of non-Big Seven Justice Leagues likely noticed some additional interesting tidbits in the form of a few throwaway lines during Ryan and Caitlin's research. The Atom says the Dorrance Glacier Boy "could be an ancestor to the same Norse folk as Ice, from the old Justice League International." This should be thrilling to Tora Olafsdottir's legions of adoring fans because it means DC has chucked the atrocious retcon of Ice's origin from Justice League: Generations Lost in favor of the original. Whatever else Ice is up to these days (she's unlikely to become a JLA regular with Killer Frost already slingin' snowballs), we can rest assured that she is likely once again a pure-hearted princess from an isolated community of ice gods, and not a generic mutant with a generic tragic origin story involving the generic accidental murder of her generic father.
I Heart the '90s
While Ryan and Caitlin experiment on the ancient ice baby, the museum is attacked -- completely unrelated to their research project -- by the villainous Terrorsmith, whose touch unleashes a person's worst fears and transforms them into a monster. Terrorsmith, aka John Mobley, first appeared in 1993's Justice League of America Annual #7, part of the Bloodlines event crossing over amongst each title's oversized annual. That event saw new heroes and villains emerge when an alien race sucked out unwitting humans' spinal fluid; the event was… not well received, though it did produce Garth Ennis and John McCrea's Hitman. In the last year, DC attempted rebooting the Bloodlines concept, but that miniseries was, again, not well received.
Terrorsmith has arrived at the museum on a quest for more power, believing that the skull of one of the alien parasites who once fed on his spine is the key to unlocking it. While the Atom holds off the guards who have been changed into monsters, Killer Frost takes down Terrorsmith -- she is, as she says, immune to his powers because she's already living her worst nightmare.
Total Eclipso the Heart
In the depths of Terrorsmith's monologues are clues about an even more powerful villain working in the background, preparing to strike. "She" gave Mobley the vision that led him to the alien's corpse, and "she has many more wishes to grant." It's not much to go on, but based on the emphasis on fear, the most likely candidate for mystery villain would have to be the Jean Loring version of Eclipso.
Though Eclipso was seen most recently possessing Maxwell Lord in the Justice League/Suicide Squad crossover, this took place before the events of "Superman Reborn," a storyline which had a ripple effect across the post-Rebirth landscape of restoring many characters -- among them, the Reverse Flash -- to their pre-Flashpoint incarnations. Eclipso would have the power to grant both visions and wishes, and the results of doing so would line up with Terrorsmith's assertion that "we'll all have something to fear." Jean Loring's involvement would also line up with this JLA series' theme of redemption and second chances, whether or not Jean herself is able to be granted such -- Jean murdered Sue Dibny, longtime JLA liaison and wife of the Elongated Man in the controversial Identity Crisis miniseries -- and as Ray Palmer's ex-wife it is certainly possible her appearance would dovetail for the search for the missing Atom.
If it's not Jean? Circe has the right power set, but she's primarily a Wonder Woman baddie and there do not seem to be any good reasons for her to appear here. A look at the '80s/'90s Justice League International yields more intriguing possibilities, especially since the current team is in many ways modeled on that iteration, and Orlando's first arc mapped so closely Giffen, DeMatteis, and Maguire's inaugural story. A reimagining of Queen Bee could work, though her mind control powers don't seem to fit what Terrorsmith is describing.
Far more likely would be a former Doctor Fate, either Inza Nelson or Linda Strauss. Justice League of America #10 begins an arc featuring the Lords of Order and Chaos, and the promo copy says that "the mysterious force known as the Might Beyond The Mirror has been granting Vanity [City]’s greatest wishes," emphasis added. It sure sounds like Terrorsmith is describing the Might, and using Inza or Linda as the embodiment of this being would check a lot of the same thematic boxes as Jean Loring. This arc could also then set up a new Doctor Fate, or else pave the way for Khalid Nassour, the most recent incarnation, to join the team.
Jean or Inza, it's very likely the Justice League will soon face off against a former friend with immense power. The question, then, is whether Batman can bring her back into the fold as he has with Killer Frost and Lobo, or if some acts are beyond redemption.