Cadmus has been lurking in the background of Supergirl for months, and Kara finally got a firsthand taste of the organization's nefarious activity in tonight’s episode, "The Darkest Places." She went into their facility to extract Mon-El, but she ran into a couple of faces she didn't expect, including Hank Henshaw, a.k.a. Cyborg Superman.

Once it was announced that Cyborg Superman was coming to Supergirl, speculation about the identity of the character flew around social media. Hank Henshaw was the number one suspect, and for good reason: he's been Cyborg Superman in the comics. Hank's initial appearance as the villain was in ADVENTURES OF SUPERMAN #500. That version of Hank was an astronaut at NASA who, after an incident with Superman, became angry and used Superman's birthing matrix to create a body mostly identical to Superman but with some artificial parts. He was set on killing the Man of Steel.

In current continuity, Cyborg Superman is actually Zor-El, Kara's father. Yeah, I'm sure those family get-togethers are interesting. I mean, he is the main villain in Supergirl's current comics right now, so... awkward is the word.

Back to the Supergirl version of Cyborg Superman. It's Hank, and he was enhanced by Cadmus. We saw proof of some cybernetic parts and his strength and invulnerability (he wasn't at all phased by Kara's punches), but we don't know the full extent of his transformation just yet, nor do we know the full scope of what Cadmus has in mind for him. Cyborg Superman used Kara's blood to gain access to information at the Fortress of Solitude. So, I can tell you this much: nothing about what Cadmus is doing is positive.

While Hank caused problems, J'onn wrestled with some of his own. The White Martian blood from M'gann mixed with his Green Martian blood and wreaked havoc. J'onn suffered from visions and nearly harmed a DEO agent because of them. Look, we all guessed how it would go when he found out the truth from M'gann. This wasn't something I expected them to hug out and get over. However, I'm disappointed in J'onn's extreme reaction. I can't relate to the anger and grief he carries, but given the themes of acceptance and tolerance that have been part of Supergirl since it premiered, I hoped he would rise above his emotions. Maybe he didn't need to forgive M'gann yet, but he certainly could have refrained from putting her in a cell at the DEO.

J'onn's still in charge of things at the DEO, but how is there not a check and balance system to keep M'gann from being detained? She didn't commit a crime. She should have been honest, yes, but she hasn't done anything malicious or harmful. She only gave J'onn her blood because he was dying; she didn't force it on him. As far as I can tell, she's only being held because J'onn's angry.

I am frustrated with J'onn, but I'm also heartbroken for him. He's been on a roller coaster. He's lived as the last of his kind for a long time. Then, he met M'gann and thought he'd found a kindred spirit. Alas, it was a lie and now he's being turned into a White Martian, the people responsible for wiping out his race. Okay. Maybe I do get why he's acting irrationally. Aren't you glad we worked that out together?

It's almost #DCTV Secrets time, but I need to bring up two more little things. First of all, I thought Winn sort of found his place in the world by taking the job with the DEO. But now that he's working with James? He's never looked happier. He's nervous about James' safety, sure, but it's obvious he's pleased about being able to contribute to another force of good. Secondly and not related at all, I applaud Snapper for calling out James on his confirmation bias.

I've been talking about one big #DCTV Secret for most of the column, but let's discuss a couple other nods to the comics and bigger DC universe.

Footage of the Guardian appears on the news while Kara and the gang are hanging out at the alien bar. Kara doesn't trust Guardian because he covers his face. She casually mentions her cousin once worked with a vigilante who had tons of gadgets... I wonder who she could possibly mean.

Guardian faced his first backlash from National City as Phillip Karnowsky swooped in wearing a suit similar to James' and started handing out death warrants. In the show, Karnowsky was motivated by vengeance. In the comics, he was known as Barrage. Karnowsky was introduced in SUPERMAN ANNUAL #2 and wore a high-tech suit of armor with built-in shock absorption and an energy cannon. He was one of Superman's villains and tangled with the Man of Steel and also Maggie Sawyer more than once.

What other #DCTV Secrets did you spot? Did you know who would be revealed as Cyborg Superman? Share all your thoughts about "The Darkest Places" in the comments.

If you enjoyed tonight's episode of Supergirl, consider picking up the Supergirl comic for much more Cyborg Superman menace. It's easy to catch up when you read it digitally.

Amy Ratcliffe covers Supergirl as a part of the #DCTV Couch Club. Look for Amy on Twitter at @amy_geek. Supergirl airs Mondays at 8 p.m. (7 p.m. CST) on The CW.