The series takes us back to a world we’ve seen in Star Trek before, but not like this.

The first half of Star Trek: Discovery's debut season ended with a white-knuckle cliffhanger, and last night the show returned with a satisfyingly action-packed episode. "Despite Yourself" revealed where our characters wound up and stoked the fires of a fan theory about Tyler's identity. It also raised some age-old questions about certain aspects of the Star Trek mythos.

Spoilers ahead. SERIOUSLY. Do not read further if you will be harmed by spoilers.

All the mirrors

One of the missions of STISCO seems to be taking the campiest tropes from ST:TOS and turning them emo and dark. Certainly that was the case with Harry Mudd, a comic relief figure from TOS whose DISCO incarnation is sarcastic and bitterly amoral. And as of last night, we're getting the DISCO reboot of the Mirror Universe that first appeared in the oft-GIF'd TOS episode "Mirror, Mirror." If you've never seen a joke about Mirror Spock's beard, you've probably never visited the Internet for any length of time.

The Mirror Universe showed up in several DS9 episodes, which also brought their fair share of campy moments. I will always treasure Mirror Kira, wearing a sparkly headband and eating grapes from the hands of her sex slaves. And it came back again in Star Trek: Enterprise, as part of that series' time travel obsession (more on that in a moment).

What do we know about the Mirror Universe? Mostly, it's just what you think. It's another universe, just like ours, except UPSIDE DOWN. Everybody's counterpart in the Mirror Universe is the opposite of who they are in our universe. So the awkward, nerdy Cadet Tilly is the brash, murderous Captain "Killy" in the Mirror Universe. The Klingons are the good guys, fighting the authoritarian, racist Terran Empire. And so on.

For those of you who (like me) screamed "WAT NO!" when Tyler killed Culber, it's important to remember that there's some timey-wimey going on in the Mirror Universe, too. Apparently you can blip around in time, as the USS Defiant did when it jumped into the Mirror Universe in the TOS episode "The Tholian Web." Captain Archer runs into the Defiant in ENT, which means he's meeting a ship from his future, trapped in an alternate timeline.

One of the fun parts of the Mirror Universe is that you get to write sentences like that. But it also means that pretty much anything can happen.

You can see why there's always something zany in Mirror Universe episodes. But STISCO is trying to go full darkness with it, emphasizing the horror of the Terran Empire's agonizer pain weapons and barbaric office politics.

How does the Terran Empire actually work?

This brings me to a question that I've always had about the Mirror Universe, but which seems particularly salient now that DISCO is actually trying to be gritty and realistic with it. How the hell does a society with no laws against murder and assault become technologically sophisticated enough to conquer parts of the galaxy? I mean, this is a question I've had about the Klingon Empire, too.

Before you start yelling at me about relatively successful-yet-murderous authoritarian regimes helmed by Mao and Stalin and Hitler, let me point out a few things. First of all, even the most bloodthirsty dictatorships in modern history didn't allow everyone to just rampantly murder their underlings. That was the right of the dictator and his cronies. Other people had to abide by the usual laws. As soon as every minor official could kill with impunity—arguably the situation in China during the Great Leap Forward, or in Cambodia under Pol Pot—productivity and innovation went into the toilet. Pol Pot would never have had the resources to usher an interstellar empire into being.

My point is that killing every competent person around you comes at a social cost. If everyone reaches a position of authority by killing their competition, you'd have very few brilliant scientists and other innovators. I mean, what kind of society do we imagine for the Terran Empire? Is the Earth just completely chaotic evil, with no education or resources for anyone unless they murder to get them? In which case, where do they get those resources, since anyone who can produce them would probably be dead?

I'm sure there's some amazingly astute answer to my questions, and I welcome it. I just find these "100-percent evil" societies even more implausible than FTL. I have no problem believing in a fascist, racist Terran Empire. But I don't think it would be run like gangland. Gangs don't scale to galactic empires. At best they become failed states.

But back to the episode

I will now pull the nitpicker stick out of my butt (ouch!) and return to taking the episode at face value. I get why we need the Mirror Universe at this point in the season. The world of DISCO is full of moral gray areas and corruption, and we need a reminder that things could always be worse. The Federation is at least on the path toward democracy, while the Terran Empire discarded democracy a long time ago.

So now we have a stark example of what could happen if the Discovery doesn't get that piece of Klingon decloaking tech back to our universe in time to save everybody. Lots of commentators have already pointed out that the Mirror Universe is a not-so-subtle reference to the rise of fascism around the world. This goes right back to its first appearance in TOS, where the Mirror Universe characters acted like Nazis. Even the Terran Empire salute, with right arm thrust out rigidly, references the Nazis.

Tyler WTF

In a nice bit of parallel plotting, "Despite Yourself" doesn't just deal with alternate universes—it also deals with alternate identities in Tyler's ever-weirdening character arc. For several episodes, fans have been wondering whether Tyler's PTSD flashbacks reveal that he's actually Klingon separatist leader Voq, surgically altered to look like Tyler. Or maybe the Klingons surgically implanted Voq's personality into Tyler's mind.

Either way, we've been teased with the possibility that Tyler and Voq now share the same brain. And that's pretty much confirmed by "Despite Yourself," when Tyler visits L'Rell in the brig and she activates his Voq side. She speaks part of a Klingon prayer to him, and he replies in Klingon. Then he snaps back into Tyler mode and L'Rell exclaims with surprise that the prayer was supposed to "bring him back."

Completely freaked out by this encounter, Tyler heads to Culber in sickbay. There, Culber's tests reveal that Tyler was actually altered in ways he didn't catch during the Lieutenant's first medical scan. Tyler's bones were cut and shortened and all his organs are scarred. Culber also mentions that there are new ways to do brainwashing in which one identity is overlaid on top of another identity. Alarmed that Culber might ground him, Tyler quickly breaks the doctor's neck and races to join Burnham and Lorca on their mission to gain control of the Shenzhou.

Obviously, Tyler's identity is fracturing, and it has everything to do with this personality stack in his brain. All the nonsense about changing the size of his bones suggests strongly that Tyler's personality was injected into Voq's surgically-altered body. Because of course a Klingon-to-human conversion would involve a little shrinkage. And of course L'Rell would choose to make Voq look like her little human sex toy. That way she gets the mind of the man she loves in the body of the man she's obsessed with.

Too bad L'Rell never watched Frankenhooker, because then she'd know that this scheme never works out the way you expect.

That said, I love that DISCO is raising all kinds of philosophical questions about identity and selfhood in the context of the Mirror Universe. What if the Tyler personality "wins" in this battle with Voq? Is he really Tyler, even though technically he's in Voq's body? Who is responsible for Culber's murder? Will Tyler become some combination of Tyler and Voq? Is there a good Voq out there in the Mirror Universe who has something to say about all of this?

Plus, there's Stamets' identity to consider. He's vacillating between milky-eyed catatonic and "I know all" wizardry. He seems to know what's happening in multiple universes and even warns Culber that "the enemy is here" right before Tyler goes homicidal.

I suspect that at least some of these questions will be answered soon. This series may be uneven, but I'm enjoying the hell out of it.

Final thought: I am really hoping that the faceless Emperor of the Mirror Universe turns out to be Mirror Philippa Georgiou, as a few people have suggested on Twitter. That would be a fun nod to a beloved character who got far too little screen time.