We first got to know J'onn J'onzz under a name that he stole to stay alive. J'onn was Supergirl's first truly great plot twist, one that completely baited comic-book fans with a plot development that flipped the first season on its head. Readers of Superman comics knew Hank Henshaw as the alter ego of a villain known as the Cyborg Superman, an evil, shape-shifting Superman impersonator who appeared following the hero's apparent death. Supergirl seemed to suggest that Hank would line up with his comic-book counterpart, only to pivot entirely and reveal him to be J'onn Jonzz, the Martian Manhunter.
"The Darkest Place" picks up that thread again, revealing that the real Hank Henshaw was saved and revived by Cadmus as the Cyborg Superman, all in support of Cadmus's xenophobic mission of alien extermination. Hank makes his return following the capture of Supergirl, which Lillian Luthor concocts by using Mon-El as leverage. In short, Kara is forced to comply with a plan that makes her temporarily mortal — by triggering her solar flare into a device designed to absorb it — so Luthor can take a sample of her blood.
It's an extremely Lex Luthor–esque plan, and Kara only agrees in order to save Mon-El's life. Afterward, they're both helpless in cells made of indestructible Nth metal until someone comes to the rescue: Jeremiah Danvers, making a sudden and brief return to save his adopted daughter and her alien friend. However, Kara isn't able to bring the DEO back in time to rescue Jeremiah. Cadmus is gone by the time they even have a chance.
Meanwhile, J'onn Jonzz — the Martian hero who has been wearing Hank Henshaw's face since Supergirl began — is suffering side effects following his blood transfusion from M'gann M'orzz, a White Martian who's been posing as a Green one. When he starts suffering hallucinations that threaten his fellow DEO agents, he asks Alex to run tests on his blood, and quickly finds out the truth about M'gann. After attacking her in fury, J'onn holds back from actually killing her, instead choosing to lock her up in the DEO — merely, it seems, for being a White Martian, and therefore being complicit in the genocide of the Green Martians — even though M'gann maintains that she took pity on the Green Martians and tried to help a few get away.
Either way, M'gann saving J'onn's life has come at a price. He is now slowly turning into a White Martian.
Truth, Justice, and Other Notes:
- James Olsen's adventures as Guardian continue to be the most misguided and trite aspect of Supergirl's second season. The story line doesn't bring anything to the table that hasn't already been thoroughly explored by any of the CW's other superhero shows. We're seeing James and Winn drag themselves into a boring show that feels like a retread of Arrow, in which normal dudes in battle gear take on normal dudes with guns and debate the importance of preserving life and keeping secrets and ugh Supergirl, you're doing everything else so well! I don't get it.
- Maggie Sawyer and Alex Danvers aren't quite finished yet, and Alex gets a pretty great scene in which she tells Maggie off for dismissing her after she came out. She says that coming out was a proud, thrilling experience. It wasn't an abstraction; it was a real feeling she had for Maggie, and now all she feels is pain because of that rejection. They end the episode tentatively open to friendship, and it's great to see Alex voice her extremely valid and very real frustration. I continue to really love this aspect of the season.
- I'm a little leery of what Cyborg Superman does with Kara's blood: He takes it to the Fortress of Solitude, uses it to fool the Fortress into thinking he's Kara, and then asks about something called Project Medusa. I'd be pretty disappointed if the season's endgame is another Kryptonian doomsday device, but we'll see. (Still crossing my fingers for Superboy.)
- Next week things are gonna get crazy interesting as Supergirl kicks off the four-part Invasion! event that will crossover with The Flash, Arrow, and Legends of Tomorrow. The promo is super coy, so there's no telling how big or small a role next week's episode will play in kicking it all off. Either way, things seem tied up well enough for a nice holiday break.