Review

Discovery's foray into the mirror universe concludes here at long last. It had begun to overstay its welcome. This ending for mirror Lorca answers most of the important questions about precisely how he got to the prime universe. It seems he switched places with prime Lorca almost two years before this episode, as it was stated that his soldiers endured 1 year and 212 days of torture. This would seem to confirm that not only was Lorca on this show always mirror Lorca, but it is quite likely that mirror Lorca commanded the prime Buran for quite some time before it was destroyed in the Klingon war and he was given command of the Discovery. Also the precise mechanics of how mirror Lorca got to the prime universe would seem to imply that it is also quite likely prime Lorca died in the process, as he would've been beamed to the I.S.S. Buran shortly before it was destroyed with all hands. As such, barring some technobabbly resurrection, there is a good chance we may never see either version of Lorca ever again.

Unfortunately the end of Lorca's story isn't terribly satisfying. From the beginning he was a character that was difficult to square in any universe. In his earlier episodes when we were led to believe he was an ordinary Starfleet captain, the narrative escalated from mere misdirection to outright lying to the audience on a number of occasions, as detailed in previous reviews. There is no coherent explanation for why Lorca didn't remember Ava's name in Vaulting Ambition other than to lie to the audience. There is no coherent explanation for why Lorca almost blew his cover in Despite Yourself other than to lie to the audience. There is no coherent explanation for why Lorca would develop an irrational obsession with turning the tardigrade into weapons in The Butcher's Knife Cares Not for the Lamb's Cry other than to lie to the audience. These are not examples of clever misdirection. They're just cheap lies to the audience to get some cheap surprises down the road.

For it to be clever misdirection, those actions would have to make sense in the context of Lorca having always been mirror Lorca. But they don't. If you rewatch all episodes of Discovery so far with the knowledge that Lorca was always mirror Lorca, you'll see that Lorca's behaviors and actions don't always make sense in the context of him being mirror Lorca in the same way that the actions of Head Six on Battlestar Galactica don't always make sense in the context of her having always been an "angel from god" instead of a chip in Baltar's head. In both cases, this eleventh hour revelation undermines the character and much of their prior actions all for the sake of cheap shock value at the expense of the story's credibility.

A better version of the Lorca story arc would've imitated how early BSG handled Boomer in the same manner that L'Rell's and Voq's sleeper agent story should have as described in previous reviews. If it was known to the audience from the beginning that Lorca was a mirror universe refugee trying to find a way home and that Tyler was Voq posing as a sleeper agent, the narrative would've had to construct a more intelligent story that makes the characters' actions make actual sense in the context of their true identities. Such an approach would've avoided all that sloppiness, would've significantly enhanced the replay value of the series, and would've been a lot more entertaining to watch in general. But who needs timeless stories with true replay value when you can throw cheap twists at the audience every week instead that fall apart if you think about them for more than five minutes?

A much more significant problem this episode creates though is the now conspicuously unresolved problem of the Discovery crew possessing foreknowledge of the Defiant's fate in TOS: The Tholian Web before it happens. This is especially compounded by bringing mirror Georgiou to the prime universe. While there is still certainly time for a future episode to button this up, It's hard to imagine why they wouldn't mention this to Starfleet so they could warn the Defiant and prevent it from being lost. Here's hoping for some kind of debate over a prototypical version of the temporal prime directive?

Some smaller lingering issues are resolved here though. For starters it's nice to see that someone found the giant distracting artificial sun thing at the center of the Charon notable enough to explain what the hell it was. Also at long last it was nice to see that Saru's threat ganglia are not in fact infallible as was repeatedly hinted at before. It's nice to see that Saru's silly danger noodles superpower won't necessarily be attenuated beyond a reasonable person's suspension of disbelief like previous Star Trek shows have done with similar characters at times. We also finally have a pretty solid answer now as to why the spore drive doesn't remain in use after Discovery: the mycelium fuel it uses is a scarce resource that can be easily exhausted in unsustainable ways by bad actors. Given that, it seems likely that someone somewhere will disrupt the fragile mycelial network to render it permanently unnavigable, if it hasn't been already in the process of getting Discovery home.

That said, could they possibly have made the danger posed by exploitation of the mycelial network more overwrought? Yes, we get it, it's a global warming metaphor. But throwing around a bunch of hyperbolic nonsense about how draining the mycelial network of its energy will destroy all life in the universe—no wait—all life in all universes is unnecessarily heavy-handed in the extreme. So basically if any civilization in any universe develops this technology and misuses it, then all life in all universes could end? Uh, sure. This kind of false profundity conjures up bad memories of TOS: The Alternative Factor, which is not a vibe that Discovery (or anything for that matter) needs to be channeling.

It was likewise quite overwrought to have the Klingon Empire conquer the Federation in the cliffhanger. While nothing in canon necessarily precludes this event, it seems a bit hard to believe nobody across hundreds of episodes and films would've mentioned that the Klingons brought the Federation to its knees at some point in the past. Plus such a dramatic reversal of fortunes significantly exacerbates the stupidity of not sending Starfleet a draft copy of that cloak-breaking algorithm they were working on in Into the Forest I Go before making the jump. This entire cliffhanger could've potentially been avoided if somebody had remembered to send an email.

All that said, even with all those narrative and plotting flaws, this is an exciting episode nonetheless. Watching ruthless mirror characters romp around and battle each other is always fun and the ridiculously well-orchestrated phaser fight in the corridor near the start of the episode might be one of Star Trek's best action sequences ever. Hidden forcefields, hidden phaser canons mounted on the wall, and an emergency site-to-site transporter escape plan. Wow! Were it not for the narrative and plotting weaknesses, this episode's sundry of well executed action sequences and thrilling character moments could've easily added up to a perfect score.