Man, this was so disappointing. This season as a whole has been so disappointing.
Starting with the worst aspect first, the Breen Primarch was fucking awful. Absolute Gargamel/Dr. Claw level villain. Every one of the scenes on the Breen ship felt like an AI upscaled version of a Saturday morning cartoon, with zero nuance and cheesy, expository dialogue. I can't even complain about the complete insanity that Moll shanked him and seemingly is the "new Primarch," because at least I don't have to deal with that one-dimensional pile of crap again. Any interesting aspects of the Breen introduced in mirrors are absent - they're just Season 1 Klingon expys in masks now.
Turning to the library, I thought it was a good concept, with a bad execution. Part of this was down to some of the production choices. Making the library look so similar to a recognizable 21st century Earth library, and having the librarian talk like a customer service representative was a...a choice. I don't think it was a good one though. It highlighted to me the stagey aspects of the show, which made it hard to suspend disbelief.
The core concept of having Michael in a sort of "mental prison" which she had to puzzle out a solution to reminded me most of the DS9 episode Move Along Home. I don't think that episode is the nadir of DS9 like some do, but that's still...not a good thing to be reminded of. Worse is unlike that episode (or other similar ones, like VOY's The Thaw) Michael is stuck in there alone, with only the AI which happens to look like Book for company. I recognize that the Trek formula often requires actors to tell rather than show, but it comes across as much more awkward when she's essentially monologuing for the convenience of the viewer. The climax, where Michael admits her insecurities, was so close to being an amazing scene, but because she was admitting it to a non-sentient pile of data, it just didn't land.
The B plot involving everyone outside of Michael's mind trying to fend off the Breen was...fine. I was really confused about why Rayner bothered to transport over and get stranded, given the XO should stay on the ship if the Captain is on an away mission, but it gave Rhys a chance to sit in the big chair, which I'm happy with. I'd rather we saw more of Owo or Detmer, but at least one of the few remaining bridge crew from Season 1 is still getting lines.
Can anyone explain to me what the hell Book was apologizing for to Michael at the start of the episode? Can anyone explain how the Discovery didn't know how to navigate the Badlands, given there's 800+ years of experience by now?
Oh, and the absolute dumbest of dumb shit - Michael giving the Breen Primarch the map to the...whatever it's going to be! Yeah, she had a double-cross planned, but still, with a Red Directive mission, and understanding the stakes (that Federation HQ, and possibly much more, will die if the Breen get there first) she should have triaged the library, and it's thousands of staff, to save millions/billions. That's what you do in command - make difficult choices. I mean, I had been wondering up until this episode how the hell Moll was going to stay in the game, with Discovery having all the clues, and the answer is just because Michael hands them all over to create artificial tension for another two episodes. ARRGH!
There were a few sections I liked. It was nice to see Rhys in command, as I noted. David Ajala was acting his heart out when he got the world tree root cutting. Rayner was great here too as well. But structurally, and in terms of execution, so, so much was either boring or actively bad here.
Even if the final two episodes are good, this is absolutely going to go down as my least favorite Discovery season now.