The best news is that we are, mercifully, done with the mirror universe for now. The second best news is that--barring some egregious violence--this was the most watchable episode of the entire series so far.
This time, they kept to a plot and even built up some tension. Burnham, I must say, was finally given a real role to play, and Sonequa Martin was able to deliver this with some moxie--in spite of having to do so beneath some fairly tone-deaf dialogue. Saru still needs more lead lines, but, quite thankfully, the writers have finally allowed him to shed some of his Kelpian passivity, and Doug Jones was deft enough to make it believable that Saru has actually grown a pair. Even behind all that ridiculous make up. And apart from a nearly endless/implausible action sequence in the throne room, the episode was the best paced episode so far.
Sadly, there is still lot of bad news....
Jason Isaacs is an incredible actor but even he couldn't pull off the impossible transformation of Mirror-Lorca-pretending-to-be-Prime-Lorca to evil, Mirror-Lorca. Why? Because impossible is hard to achieve. Again, it's very hard to see how even a very cunning Mirror-Lorca could sublimated his evil inclinations and mirror-universe impulsivity enough to last 10 minutes in Federation space. I'm sorry. Now that we see how much of a loose cannon he is on his home turf, he would have been outed trying to take a bite out of Saru's left arm 5 minutes after entering Prime space. You can't have it both ways.
He proved it this episode by his rash takeover of the Empress' ship, only to lose it to the (literal) one-two punch of the Empress and Burnham. Sure Lorca has always been mavricky and the writers, last week, were fond of giving us 'clues' in flashbacks that he was really, truly Mirror-Lorca. However, looking back, all that stuff didn't really amount to a hill of beans and it almost seems as though they could have gone either way with the character if this was one of those choose-your-own-adventure books. (What's sad is that if he were Prime Lorca he'd be a lot more interesting character: the somewhat damaged, former captain of the USS Buran who didn't go down with his ship and who isn't beyond some level of recklessness so long as it punishes the Klingons.)
If Lorca is so malevolently brilliant to pull such a quick coup de starship, how did he miss the fact that Burnham would double cross him in the end. And how in that nearly endless/mostly pointless, Marvel-comic, two-against-like-20 action sequence in the wide-open throne room where they were sitting ducks, did Burnham and Georgiou dispatch of all of Lorca's henchman... with no plan other than, 'let's surprise them.' Holy Here We Go Again, Batman! Really?
And why, why, why did we get rid of Lorca, one of the best characters in the series so far? Given that Lorca is Gabriel and Burnham is Michael, it seems somehow unlikely that the writers would so easily give up one of their Archangels. (That said, if we find out that Prime-Lorca had been waylayed and tied up by Mirror-Lorca all this time and is ripe for the findin' now that our crew is back in Prime, this would be just another cheap twist of the plot thumb screws by our over zealous team of writers.) And how did Lorca get to Prime? Did he learn about the Discovery and deliberately go to Prime as part of a nefarious plot? (Cue evil laugh.) Nope. Transporter accident/just dumb luck. Ugh. The writers failed us again.
And then there is Tilly, who seems to be growing more and more gray matter with each episode. Maybe the writers intended that she is some kind of secret genius. But at this point we have a cadet running engineering while the chief engineer is non compos mentis micilia and now that he's back she seems to be the only one that can figure out how to save the Discovery from almost certain doom and gloom. Then we have the two of them engage in near-technobabble regarding how to the Discovery will survive, with Stamets concluding that it is possible but will be--what is that scientific word? Oh, yeah, 'hard.' Umm. .
Then we have the kill-the-death-star sequence, with Discovery running the trench like the rebel fleet trying to snuff out the mycelial powerball on the Empress' ship. The difference, of course is that Luke Skywalker was actually pursued by Tie fighters and Darth Vader had Luke in his sights. Here, we only had a few ship-side phaser canons and a quip from the chief security officer asking if the containment field was up. Oops. One quick fly through and blammo! (So much for building tension.)
Then, of course, Stamets finds his way back to another bizzare micelial dream sequence involving Culber telling him to follow the music. This was very hard to take. No amount of extended editing sequence involving rapid-flash sequences of Stamets, surprised crew members, and discovery riding miclelial waves could build any tension here when you knew they would absolutely make it back safe and sound.
Oh. And how did we get back to universe Prime? The mycleial drive. So why, oh why, was Burnham on the suicide mission on the Empress' ship? To get the data on the Defiant. So the whole drek about the Defiant data was--yes--just another contrived plot device to get characters in position for another reason. At some point, though, it would be nice if our crew would go on a mission for some reason other than that it puts them in the right place at the right time to drive another plot line.
Which leaves our dear crew back in the Prime universe, nine months after they left, with no response from the Federation and the Klingons winning the war.
And that, at least, my friends, might be a promising premise for the next episode and another chance to hit the reset button.